Adolescent Body Mass Index and Early Chronic Kidney Disease in Young Adulthood

Importance

Despite increasing obesity rates in adolescents, data regarding early kidney sequelae are lacking.

Objective

To assess the association between adolescent body mass index (BMI) and early chronic kidney disease (CKD) in young adulthood (<45 years of age).

Design, Setting, and Participants

This cohort study linked screening data of mandatory medical assessments of Israeli adolescents to data from a CKD registry of a national health care system. Adolescents who were aged 16 to 20 years; born since January 1, 1975; medically evaluated for mandatory military service through December 31, 2019; and insured by Maccabi Healthcare Services were assessed. Individuals with kidney pathology, albuminuria, hypertension, dysglycemia, or missing blood pressure or BMI data were excluded. Body mass index was calculated as weight in kilograms divided by height in meters squared and categorized by age- and sex-matched percentiles according to the US Centers for Disease Control and Prevention. Follow-up started at the time of medical evaluation or January 1, 2000 (whichever came last), and ended at early CKD onset, death, the last day insured, or August 23, 2020 (whichever came first). Data analysis was performed from December 19, 2021, to September 11, 2023.

Main Outcomes and Measures

Early CKD, defined as stage 1 to 2 CKD by moderately or severely increased albuminuria, with an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or higher.

Results

Of 629 168 adolescents evaluated, 593 660 (mean [SD] age at study entry, 17.2 [0.5] years; 323 293 [54.5%] male, 270 367 [45.5%] female) were included in the analysis. During a mean (SD) follow-up of 13.4 (5.5) years for males and 13.4 (5.6) years for females, 1963 adolescents (0.3%) developed early CKD. Among males, the adjusted hazard ratios were 1.8 (95% CI, 1.5-2.2) for adolescents with high-normal BMI, 4.0 (95% CI, 3.3-5.0) for those with overweight, 6.7 (95% CI, 5.4-8.4) for those with mild obesity, and 9.4 (95% CI, 6.6-13.5) for those with severe obesity. Among females, the hazard ratios were 1.4 (95% CI, 1.2-1.6) for those with high-normal BMI, 2.3 (95% CI, 1.9-2.8) for those with overweight, 2.7 (95% CI, 2.1-3.6) for those with mild obesity, and 4.3 (95% CI, 2.8-6.5) for those with severe obesity. The results were similar when the cohort was limited to individuals who were seemingly healthy as adolescents, individuals surveyed up to 30 years of age, or those free of diabetes and hypertension at the end of the follow-up.

Conclusions and Relevance

In this cohort study, high BMI in late adolescence was associated with early CKD in young adulthood. The risk was also present in seemingly healthy individuals with high-normal BMI and before 30 years of age, and a greater risk was seen among those with severe obesity. These findings underscore the importance of mitigating adolescent obesity rates and managing risk factors for kidney disease in adolescents with high BMI.

Statistical Methods and Machine Learning Algorithms for Investigating Metabolic Syndrome in Temporomandibular Disorders: A Nationwide Study

The objective of this study was to analyze the associations between temporomandibular disorders (TMDs) and metabolic syndrome (MetS) components, consequences, and related conditions. This research analyzed data from the Dental, Oral, Medical Epidemiological (DOME) records-based study which integrated comprehensive socio-demographic, medical, and dental databases from a nationwide sample of dental attendees aged 18-50 years at military dental clinics for 1 year. Statistical and machine learning models were performed with TMDs as the dependent variable. The independent variables included age, sex, smoking, each of the MetS components, and consequences and related conditions, including hypertension, hyperlipidemia, diabetes, impaired glucose tolerance (IGT), obesity, cardiac disease, obstructive sleep apnea (OSA), nonalcoholic fatty liver disease (NAFLD), transient ischemic attack (TIA), stroke, deep venous thrombosis (DVT), and anemia. The study included 132,529 subjects, of which 1899 (1.43%) had been diagnosed with TMDs. The following parameters retained a statistically significant positive association with TMDs in the multivariable binary logistic regression analysis: female sex [OR = 2.65 (2.41-2.93)], anemia [OR = 1.69 (1.48-1.93)], and age [OR = 1.07 (1.06-1.08)]. Features importance generated by the XGBoost machine learning algorithm ranked the significance of the features with TMDs (the target variable) as follows: sex was ranked first followed by age (second), anemia (third), hypertension (fourth), and smoking (fifth). Metabolic morbidity and anemia should be included in the systemic evaluation of TMD patients.

Hypermobility spectrum disorders and irritable bowel syndrome: A nationwide study of 1.6 million adolescents

BACKGROUND AND AIM

The association between hypermobility spectrum disorders/hypermobile type Ehlers-Danlos syndrome (HDS/hEDS) and irritable bowel syndrome (IBS) is yet to be clarified. We aimed to assess this association in a national sample of adolescents.

METHODS

A population-based cross-sectional study included 1 627 345 Israeli adolescents (58% male; mean age 17 years) who were medically assessed before compulsory military service during 1998-2020. Diagnoses of HSD/hEDS and IBS were confirmed by board-certified specialists. The prevalence and odds ratios (ORs) for IBS in adolescents with and without HSD/hEDS were computed.

RESULTS

A total of 4686 adolescents (2553 male) with HSD/hEDS were identified, of whom 71 were diagnosed with IBS (prevalence = 1.5%). Of the 1 621 721 adolescents in the control group, 8751 were diagnosed with IBS (prevalence = 0.5%). Unadjusted logistic regression revealed a significant association between HSD/hEDS and IBS (OR = 2.16 [95% confidence interval, CI, 1.90-2.45]), which persisted in multivariable adjusted models (OR = 2.58 [95% CI, 2.02-3.24]), and in several sensitivity analyses. The association was evident in both male and female adolescents with ORs of 2.60 (95% CI, 1.87-3.49), and 2.46 (95% CI, 1.66-3.49), respectively. The association was accentuated in a sensitivity analysis accounting for other medical and psychiatric comorbidities.

CONCLUSIONS

We found a significant association between HSD/hEDS and IBS in both male and female adolescents. Clinical awareness of the association can promote early diagnosis of IBS and appropriate multidisciplinary treatment. Further research is required to identify the common pathological pathways of the conditions and to develop new IBS treatment strategies for people with HSD/hEDS.

Periodontitis and Metabolic Syndrome: Statistical and Machine Learning Analytics of a Nationwide Study

This study aimed to analyze the associations between periodontitis and metabolic syndrome (MetS) components and related conditions while controlling for sociodemographics, health behaviors, and caries levels among young and middle-aged adults. We analyzed data from the Dental, Oral, and Medical Epidemiological (DOME) record-based cross-sectional study that combines comprehensive sociodemographic, medical, and dental databases of a nationally representative sample of military personnel. The research consisted of 57,496 records of patients, and the prevalence of periodontitis was 9.79% (5630/57,496). The following parameters retained a significant positive association with subsequent periodontitis multivariate analysis (from the highest to the lowest OR (odds ratio)): brushing teeth (OR = 2.985 (2.739-3.257)), obstructive sleep apnea (OSA) (OR = 2.188 (1.545-3.105)), cariogenic diet consumption (OR = 1.652 (1.536-1.776)), non-alcoholic fatty liver disease (NAFLD) (OR = 1.483 (1.171-1.879)), smoking (OR = 1.176 (1.047-1.322)), and age (OR = 1.040 (1.035-1.046)). The following parameters retained a significant negative association (protective effect) with periodontitis in the multivariate analysis (from the highest to the lowest OR): the mean number of decayed teeth (OR = 0.980 (0.970-0.991)); North America as the birth country compared to native Israelis (OR = 0.775 (0.608-0.988)); urban non-Jewish (OR = 0.442 (0.280-0.698)); and urban Jewish (OR = 0.395 (0.251-0.620)) compared to the rural locality of residence. Feature importance analysis using the eXtreme Gradient Boosting (XGBoost) machine learning algorithm with periodontitis as the target variable ranked obesity, OSA, and NAFLD as the most important systemic conditions in the model. We identified a profile of the "patient vulnerable to periodontitis" characterized by older age, rural residency, smoking, brushing teeth, cariogenic diet, comorbidities of obesity, OSA and NAFLD, and fewer untreated decayed teeth. North American-born individuals had a lower prevalence of periodontitis than native Israelis. This study emphasizes the holistic view of the MetS cluster and explores less-investigated MetS-related conditions in the context of periodontitis. A comprehensive assessment of disease risk factors is crucial to target high-risk populations for periodontitis and MetS.

Body mass index and migraine in adolescence: A nationwide study

BACKGROUND

The association between body mass index (BMI) and migraine in adults has been well established. However, studies in children and adolescents are inconclusive. We aimed to study the association between BMI and migraine using a national dataset that comprises the electronic medical records of more than two million adolescents.

METHODS

This study included all Israeli adolescents (57.7% males, 42.3% females; mean age 17 years) who were medically assessed before mandatory military service during 1990-2020. As part of the pre-recruitment medical assessment, all the adolescents were screened for migraine and their height and weight were measured. Diagnoses of migraine were confirmed by board-certified neurologists. Prevalences and odds ratios (ORs) for migraine were computed across BMI subgroups. Spline models were applied.

RESULTS

A total of 2,094,862 adolescents were included, of whom 57,385 (2.8%) had active migraine. Among males, the adjusted ORs for migraine were 1.11 (95% confidence interval, 1.06-1.16), 1.13 (1.08-1.17), and 1.24 (1.19-1.30), for the underweight, overweight, and obesity subgroups, respectively, compared to the reference group of low-normal BMI (5th-49th percentile). Among females, the respective adjusted ORs were 1.12 (1.05-1.19), 1.23 (1.19-1.28), and 1.38 (1.31-1.46). Results persisted in sensitivity analyses accounting for other medical and psychiatric comorbidities and parental history of migraine. Spline models demonstrated a J-shaped relation between BMI and migraine.

CONCLUSIONS

Both adolescent obesity and underweight were associated with migraine in a sex-dependent manner. This association peaked in female adolescents with overweight and obesity.

Association Between Body Mass Index and Nonspecific Recurrent Low Back Pain in Over 600,000 Healthy Young Adults

An association between body mass index (BMI; weight (kg)/height (m)2) and low back pain (LBP) has long been debated, but inconsistent measurements of BMI and varying definitions of LBP have produced conflicting findings. We explored this association using measured BMI and physician documentation of recurrent LBP among healthy young adults. Data were extracted from the Israel Defense Forces electronic medical record system. All Israeli citizens with compulsory military service during January 2008-March 2019 were included (n = 705,840). Exclusion criteria were spine deformities, disc pathologies, spinal surgeries, arthropathies, connective tissue diseases, pain syndromes, low bone density disorders, cancers, and psychiatric illnesses. LBP was defined as electronic medical record system documentation of 1) 2 medical visits at least 6 weeks apart with a diagnosis of LBP or "LBP with radiation" or 2) 1 medical visit resulting in referral to an orthopedic surgeon. Logistic regression models were used to explore the association between BMI category and LBP; 619,969 (87.8%) individuals (mean age = 18.9 (standard deviation, 0.97) years; 56.9% male) were included. LBP prevalence was 9.2% (n = 56,918) and higher among males (9.7%) than females (8.5%). Overweight (odds ratio = 1.123, 95% confidence interval: 1.096, 1.151) and obesity (odds ratio = 1.137, 95% confidence interval: 1.096, 1.179) were associated with LBP. The association remained significant after accounting for various sociodemographic factors. Maintaining a healthy BMI may aid in the prevention of LBP in young adults.

Adolescent BMI and Cognitive Performance: A Nationwide Study of 2.48 Million Israeli Adolescents

OBJECTIVE

The increased incidence of adolescent obesity over recent decades may be associated with lower cognitive performance than the expected potential. Thus, we aimed to assess the association between adolescent body mass index (BMI) and cognitive function.

DESIGN

A nationwide, cross-sectional, population-based study including all Israeli-born adolescents, 1,459,522 males and 1,027,953 females aged 16 to 20 years old, who were evaluated for military service during 1967-2018.

METHODS

Weight and height were measured to calculate BMI. Cognitive performance was assessed by a validated Intelligence-Quotient-equivalent test and was standardized to the year- and sex-Z-score. For 445,385 persons, parental cognitive scores could be identified. Multinomial logistic regression models were applied.

RESULTS

Among male adolescents with severe obesity, 29.4% achieved a cognitive score below the 25th percentile, compared to 17.7% among their normal-weight (50th-84th percentile) counterparts. A largely J-shaped relation was observed between BMI and the odds ratio (OR) for a low cognitive score among male adolescents: underweight, 1.45 (1.43-1.48); overweight, 1.13 (1.12-1.15); mild obesity, 1.36 (1.33-1.39); and severe obesity, 1.58 (1.52-1.64). Similar findings were observed in females. For both sexes, point estimates were overall consistent in models adjusted for sociodemographic confounders, coexisting morbidities and parental cognitive scores. Examinees with abnormal BMI had higher ORs for lower-than-expected cognitive score, based on their parents' data as adolescents, in a manner that depends on obesity severity.

CONCLUSION

Abnormal BMI, and especially obesity, is associated with increased odds for a lower cognitive performance, and the inability to fully achieve cognitive potential, regardless of sociodemographic background.

Hypermobility spectrum disorders and active migraine in Israeli adolescents: A nationwide study

OBJECTIVE

To assess the association between hypermobility spectrum disorders/hypermobile type Ehlers Danlos Syndrome (HSD/hEDS) and migraine in a national sample of adolescents in Israel.

BACKGROUND

The association between HSD/hEDS and migraine is unclear, even more so in pediatric populations.

METHODS

This population-based, cross-sectional study included 1,627,345 Israeli adolescents (945,519/1,626,407 [58%] males; mean age 17 ± 0.5 years) who were medically assessed before mandatory military service during 1998-2020. Diagnoses of migraine with at least one attack per month (active migraine) and HSD/hEDS were confirmed by certified specialists. The prevalences of active migraine in adolescents with and without HSD/hEDS were computed and the association between HSD/hEDS and active migraine was examined.

RESULTS

Active migraine was significantly more prevalent in adolescents with HSD/hEDS (307/4686 [6.5%]) compared to those without HSD/hEDS (51,931/1,621,721 [3.2%]) (OR = 2.16, 95% CI 1.90-2.45). The association between HSD/hEDS and active migraine persisted in a multivariable analysis (OR = 2.08, 95% CI 1.85-2.34) and in several sensitivity analyses.

CONCLUSIONS

We found a significant association between HSD/hEDS and active migraine in both male and female adolescents. Clinical awareness of the association can promote early diagnosis and treatment of migraine. Further research is required to identify appropriate pharmacologic and nonpharmacologic migraine treatment strategies for individuals with HSD/hEDS.

COVID-19 vaccination - Does it affect sick leave in military personnel?

OBJECTIVE

Sick leave is a major negative economic effect of the COVID-19 pandemic. In April 2021, the Integrated Benefits Institute reported that employers spent a total of US $50.5 billion for workers absent due to the COVID-19 pandemic. While vaccination programs lowered the number of severe illness and hospitalizations worldwide, the number of side effects following vaccination against COVID-19 were high. The present study aimed to evaluate the effect of vaccination on the probability of taking sick leave in the week following vaccination.

SUBJECTS AND METHODS

The study population was comprised of all personnel serving in the Israel Defense Forces (IDF) between October 7, 2020, and October 3, 2021, (a total of 52 weeks) who were vaccinated with at least one dose of the BNT162b2 vaccine. Data on Israel Defense Forces (IDF) personnel sick leaves were retrieved and the probability of a "post-vaccination week sick leave" and a "regular (not post-vaccination week) sick leave" were analyzed. An additional analysis was performed to determine whether winter-related diseases or the sex of the personnel affected the probability of taking sick leave.

RESULTS

The probability of taking sick leave in a post-vaccination week was significantly higher than the probability of taking sick leave in a regular week (8.45% vs. 4.3%, respectively, p < 0.01). The increased probability remained unchanged after analysis of sex-related and winter disease-related variables.

CONCLUSIONS

Given the major effect of vaccination against COVID-19 by BNT162b2 vaccine on the probability of taking sick leave, when medically feasible, the timing of the vaccination should be considered by medical, military, and industrial authorities with the intent to minimize the effect on overall national economy and safety.

Is There an Association between BMI, Height, and Gender and Long-Bone Fractures during Childhood and Adolescence? A Large Cross-Sectional Population Study of 911,206 Subjects

INTRODUCTION

Traumatic long-bone fractures (TLFs) among children and adolescents are relatively common, with morbidity and economic consequences. Obesity has become a significant global concern. Studies have found an association between TLFs and BMI in the past but not in a large cross-sectional population study. Our study objective was to measure the incidence of TLFs in the 17-year-old general population and evaluate its association with BMI, body height, and gender.

METHODS

Data from a medical database containing all 17-year-old candidates' records before recruitment into mandatory military service were retrieved as BMI, height, gender, and history of TLFs. Logistic regression models assessed the association between BMI and height to TLFs.

RESULTS

The records of 911,206 subjects (515,339 males) were reviewed. In total, 9.65% had a history of TLFs (12.25% and 6.25% for males/females, respectively). Higher BMI was associated with TLF, with a linear trend in the odds ratio (OR) for having TLFs. The strongest association was found between obese females and TLFs (OR = 1.364, p < 0.0001). Height was an independent factor positively associated with TLFs. The OR for a TLF in the highest height quintile was 1.238 (p < 0.001) for males and 1.411 (p < 0.001) for females compared to the lowest quintile. Although TLFs were more common in males, the OR for TLFs was more prominent in females.

CONCLUSIONS

There is an association between BMI, body height, and TLFs in healthy adolescents. TLFs are more common in males, but the strongest association between overweight and obesity is evident in females.

Adolescent Hypertension Is Associated With Stroke in Young Adulthood: A Nationwide Cohort of 1.9 Million Adolescents

BACKGROUND

Adult hypertension is a well-established risk factor for stroke in young adults (aged <55 years), and the effects are even more deleterious than at an older age. However, data are limited regarding the association between adolescent hypertension and the risk of stroke in young adulthood.

METHODS

A nationwide, retrospective cohort study of adolescents (aged 16-19 years) who were medically evaluated before compulsory military service in Israel during 1985 to 2013. For each candidate for service, hypertension was designated after constructed screening, and the diagnosis was confirmed through a comprehensive workup process. The primary outcome was ischemic and hemorrhagic stroke incidence as registered at the national stroke registry. Cox proportional-hazards models were used. We conducted sensitivity analyses by excluding people with a diabetes diagnosis at adolescence or a new diabetes diagnosis during the follow-up period, analysis of adolescents with overweight, and adolescents with baseline unimpaired health status.

RESULTS

The final sample included 1 900 384 adolescents (58% men; median age, 17.3 years). In total, 1474 (0.08%) incidences of stroke (1236 [84%] ischemic) were recorded, at a median age of 43 (interquartile range, 38-47) years. Of these, 18 (0.35%) occurred among the 5221 people with a history of adolescent hypertension. The latter population had a hazard ratio of 2.4 (95% CI, 1.5-3.9) for incident stroke after adjustment for body mass index and baseline sociodemographic factors. Further adjustment for diabetes status yielded a hazard ratio of 2.1 (1.3-3.5). We found similar results when the outcome was ischemic stroke with a hazard ratio of 2.0 (1.2-3.5). Sensitivity analyses for overall stroke, and ischemic stroke only, yielded consistent findings.

CONCLUSIONS

Adolescent hypertension is associated with an increased risk of stroke, particularly ischemic stroke, in young adulthood.

Familial clustering of psychiatric disorders and low IQ

BACKGROUND

Although the ICD and DSM differentiate between different psychiatric disorders, these often share symptoms, risk factors, and treatments. This was a population-based, case-control, sibling study examining familial clustering of all psychiatric disorders and low IQ, using data from the Israel Draft-Board Registry on all Jewish adolescents assessed between 1998 and 2014.

METHODS

We identified all cases with autism spectrum disorder (ASD, N = 2128), severe intellectual disability (ID, N = 9572), attention-deficit hyperactive disorder (ADHD) (N = 3272), psychotic (N = 7902), mood (N = 9704), anxiety (N = 10 606), personality (N = 24 816), or substance/alcohol abuse (N = 791) disorders, and low IQ (⩾2 SDs below the population mean, N = 31 186). Non-CNS control disorders were adolescents with Type-1 diabetes (N = 2427), hernia (N = 29 558) or hematological malignancies (N = 931). Each case was matched with 10 age-matched controls selected at random from the Draft-Board Registry, with replacement, and for each case and matched controls, we ascertained all full siblings. The main outcome measure was the relative recurrence risk (RRR) of the sibling of a case having the same (within-disorder RRR) or a different (across-disorder RRR) disorder.

RESULTS

Within-disorder RRRs were increased for all diagnostic categories, ranging from 11.53 [95% confidence interval (CI): 9.23-14.40] for ASD to 2.93 (95% CI: 2.80-3.07) for personality disorders. The median across-disorder RRR between any pair of psychiatric disorders was 2.16 (95% CI: 1.45-2.43); the median RRR between low IQ and any psychiatric disorder was 1.37 (95% CI: 0.93-1.98). There was no consistent increase in across-disorder RRRs between the non-CNS disorders and psychiatric disorders and/or low IQ.

CONCLUSION

These large population-based study findings suggest shared etiologies among most psychiatric disorders, and low IQ.

Glucose intolerance in pregnancy and risk of early-onset type 2 diabetes: a population-based cohort study

BACKGROUND

The risk of type 2 diabetes among women with glucose intolerance during pregnancy that does not meet gestational diabetes criteria requires further investigation. We aimed to explore the associations between various degrees of gestational glucose intolerance and the risk of type 2 diabetes in young adulthood.

METHODS

For this population-based cohort study, the national Israeli conscription database was linked to Maccabi Healthcare Services (MHS), the second-largest state-mandated health provider in Israel. We included 177 241 women who underwent a pre-recruitment evaluation at adolescence (age 16-20 years), 1 year before mandatory military service, and later underwent, from Jan 1, 2001, to Dec 31, 2019, two-step gestational diabetes screening with a 50 g glucose challenge test (GCT) based on a threshold of 140 mg/dL (7·8 mmol/L), followed as needed by a 100 g oral glucose tolerance test (OGTT). Abnormal OGTT values were defined according to the Carpenter-Coustan thresholds: 95 mg/dL (5·3 mmol/L) or higher in the fasting state; 180 mg/dL (10·0 mmol/L) or higher at 1 h; 155 mg/dL (8·6 mmol/L) or higher at 2 h; and 140 mg/dL (7·8 mmol/L) or higher at 3 h. The primary outcome was incident type 2 diabetes in the MHS diabetes registry. Cox proportional hazards models were applied to estimate adjusted hazard ratios (HRs) with 95% CIs for incident type 2 diabetes.

FINDINGS

During a cumulative follow-up of 1 882 647 person-years, and with a median follow-up of 10·8 (IQR 5·2-16·4) years, 1262 women were diagnosed with type 2 diabetes. Crude incidence rates of type 2 diabetes were 2·6 (95% CI 2·4-2·9) per 10 000 person-years in women with gestational normoglycaemia, 8·9 (7·4-10·6) per 10 000 person-years in women with an abnormal GCT and normal OGTT, 26·1 (22·4-30·1) per 10 000 person-years in women with one abnormal OGTT value (in the fasting state or 1 h, 2 h, or 3 h post-challenge), and 71·9 (66·0-78·3) per 10 000 person-years in women with gestational diabetes. After adjustment for sociodemographic characteristics, adolescent BMI, and age at gestational screening, the risk of type 2 diabetes was higher, compared to the gestational normoglycaemia group, in women with an abnormal GCT and normal OGTT (adjusted hazard ratio [HR] 3·39 [95% CI 2·77-4·16]; p<0·0001), in women with one abnormal OGTT value (9·11 [7·64-10·86]; p<0·0001), and in women with gestational diabetes (24·84 [21·78-28·34]; p<0·0001). The risk of type 2 diabetes was modestly increased in women with isolated elevated fasting glucose (adjusted HR 11·81 [95% CI 8·58-16·25]; p<0·0001), and in women with gestational diabetes and an abnormal fasting glucose (38·02 [32·41-44·61]; p<0·0001).

INTERPRETATION

Gestational glucose intolerance, including conditions not meeting gestational diabetes criteria of the two-step strategy, confers a high risk of type 2 diabetes in young adulthood. These conditions should be recognised as risk factors for type 2 diabetes, especially among women with abnormal fasting glucose concentrations during pregnancy.

FUNDING

None.

Predictors of combat training attrition in Israel Defense Forces soldiers

BACKGROUND

Attrition from combat service carries significant organizational and personal ramifications, but predicting factors associated with attrition remains challenging.

AIMS

To evaluate medical and psychosocial factors associated with attrition from basic combat training (BCT) in the Israel Defense Forces (IDF). In addition, we identify subsets of the recruit population which exhibit certain trends in terms of medical corresponding with a high risk of attrition.

METHODS

A cross-sectional study of IDF combat trainees undergoing infantry BCT between 2012 and 2017. Data were collected from the soldiers' electronic medical and administrative records. We used multivariable logistic regression and the SAS® decision-tree tool to analyse key predictive factors for attrition.

RESULTS

A total of 46 472 soldiers enlisted to BCT during the research period. The mean body mass index (BMI) was 21.8 (SD 3.54). The overall attrition rate was 10%. The following factors were associated with attrition from BCT: ethnicity (P < 0.01), BMI (P < 0.01), pre-enlisting motivation score (P < 0.01) and the number of mental health officer visits (P < 0.01). Using a decision-tree model, we found a high attrition rate among soldiers who had >5.2 to primary care physician visits (11% attrition rate versus 3%) or more than 11 sick leave days (59% versus 19%).

CONCLUSIONS

This study sheds light on unique measures relating to attrition. Attrition is associated with several demographic and psychosocial factors. Early prediction of motivation and monitoring of healthcare utilization may enable early identification and focused interventions targeting soldiers at high risk for attrition. These findings need to be further translated into actionable directives and further investigations.

Occupational Exposure to Nonionizing Radiation and Risk for Malignancy in Young Adults

INTRODUCTION

Nonionizing radiation (NIR) is considered "possibly carcinogenic to humans," and therefore, exposure of young military personnel raises concerns regarding increased risk for cancer. The aim of our study was to compare the cancer incidence in exposed and nonexposed populations in order to gain better understanding of their risk.

MATERIALS AND METHODS

A longitudinal retrospective cohort study, between 2009 and 2018, was conducted. Israel Defense Forces (IDF) aerial defense units service members, with NIR exposure (range of 2-300 GHz, below the International Commission of Non-Ionizing Radiation Protection guidelines), were compared with a similar sociodemographic group of service members without NIR exposure. Both groups were followed for cancer incidence (all-cause and specific malignancies). Kaplan-Meier analysis of cancer-free survival and univariate and multivariable logistic regressions for possible confounders and risk factors were performed. This analysis was repeated on a matched 1:1 control group.

RESULTS

Exposure and comparison groups included 3,825 and 11,049 individuals, respectively. Forty-one cases diagnosed with cancer were identified during the follow-up time (mean 4.8 [±2.7] years), 13 (0.34%) of which were reported in the exposure group, and 28 (0.25%) were reported in the comparison group. The odds ratio (OR) for cancer incidence in the exposure vs. control groups was 1.34 (95%CI, 0.70-2.60), P-value = 0.3807. The results remained unchanged after adjustment for sex, age at enrollment, service length, socioeconomic status, and military occupation (adjOR = 1.38 [95%CI, 0.67-2.82], P = 0.3818).

CONCLUSIONS

Our study did not find an increased short-term risk for cancer in young adults exposed to NIR radiation as compared with unexposed young adults.

Being overweight and born in the spring are associated with an increased risk for rhinitis

AIM

To explore the relationship between the season of birth and the prevalence of recurrent or chronic rhinitis (rhinitis).

METHODS

The medical records of consecutive 17-year-old conscripts to the Israeli army were reviewed. We compared the prevalence of rhinitis between children born during different seasons. Multivariate analysis was performed with additional variables.

RESULTS

The prevalence of rhinitis among the 1.1 million recruits was 7.1% in males and 5.3% in females. The association between birth season and the prevalence of rhinitis was highly significant (p < 0.001 for both genders). Spring was the birth season with the highest prevalence of rhinitis (7.4% in males and 5.5% in females). Males born in the winter and females born in the autumn had the lowest prevalence of rhinitis (6.7%, and 5.2% respectively). There was an increased odds ratio for rhinitis among those with a body mass index above 25, higher cognitive score and maternal birth country out of Israel or Africa.

CONCLUSIONS

There was an increased risk of rhinitis among young Israeli adults who were born in the spring, were overweight and had a higher cognitive-score. Family planning to avoid a spring birth and preventing overweight may reduce the risk of chronic rhinitis.

RF28 | PSUN302 Obesity at Late Adolescence and Incident Type 1 Diabetes in Young Adulthood

Aims

Studies in children reported an association between increased body mass index (BMI) and risk for developing type 1 diabetes (T1D), but evidence in late adolescence is limited. We recently investigated the association between adolescent BMI and type 2 diabetes in young adulthood (Diabetes Care 2020, 43(7): 1487-95) and here we studied on the same cohort the association between late adolescent BMI and incident T1D.

Methods

All Israeli adolescents, ages 16-19, undergoing medical evaluation in preparation for mandatory military conscription between January 1996 and December 2016 were included for analysis unless they had a history of dysglycemia (n=1,462,362; 40% women). Data were linked to information about adult onset of T1D in the Israeli National Diabetes Registry. Weight and height were measured at study entry and BMI was computed and transformed to age- and sex-adjusted BMI percentiles according to US Center for Diseases Control. The definition of T1D was determined based on anti-diabetic drugs and was confirmed for a subpopulation of the cohort to which islet autoantibodies data were available. Cox proportional models were applied, with BMI analyzed both as a categorical and continuous variable.

Results

There were 777 incident cases of T1D during 15,810,751 person-years (mean age at diagnosis 25.2±3.9 years). The median follow-up period was 11.2 years (IQR 5.8-16.3), with follow-up length shorter for individuals with a higher BMI. The crude diabetes rate showed a consistent graded increase across BMI groups from underweight to obesity; 3.6 to 8.4 cases per 100,000 person-years, respectively.

In a multivariable model adjusted for age, sex and socio-demographic variables, the hazard ratios (HRs) for T1D were 1.05 (95% CI 0.87-1.27) for the 50th–74th BMI percentiles, 1.41 (1.11–1.78) for the 75th–84th BMI percentiles, 1.54 (1.23–1.94) for adolescents with overweight (85th–94th percentiles), and 2.05 (1.58–2.66) for adolescents with obesity (BMI≥95th percentile)(reference group, 5th-49th BMI percentile group). One increment in BMI standard deviation was associated with 25% greater risk for incidence of T1D (HR=1.25, 95%CI 1.17-1.32). when the presence of one or multiple (≥2) islet antibodies was added as a criterion for T1D definition, the HRs among those with adolescent obesity were 2.90 (1.80-4.68) and 3.14 (1.68-5.88) respectively. Results were marginally affected by level of adjustment for sociodemographic background, were similar when analysis was stratified by sex, and also persisted when the study population was limited to adolescents with unimpaired health in order to mitigate confounding by coexisting illness.

The fraction of type 1 diabetes attributed to adolescent overweight and obesity (Population attributable risk%; PAR%) was 10.1% (95%CI 6.3%-14.2%).

Conclusions

Adolescent overweight and obesity in apparently healthy adolescents were associated with increased risk for incident type 1 diabetes in early adulthood.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 1:24 p.m. - 1:30 p.m.

Varicocele in adolescence and testicular cancer in young adulthood

BACKGROUND

Elevated intrascrotal temperature has been suggested as a risk factor for testicular cancer, which is the most common neoplasm among young men. Varicocele was linked to increased intrascrotal temperature, but whether it is associated with testicular cancer is unclear.

OBJECTIVE

To explore the possible association between varicocele at adolescence and the incidence of testicular cancer at adulthood.

DESIGN, SETTING AND PARTICIPANTS

This nationwide, population-based, historical cohort study includes 1,521,661 Israeli male adolecents (mean age 17.5 ± 0.4 years), who were screened for varicocele during the years 1967-2012, as part of their medical assessment prior to compulsory military service. The mean follow-up was 18± 4.2 years.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The diagnosis of testicular cancer was ascertained from linkage of records to the the Israeli National Cancer Registry. Survival analysis was applied.

RESULTS

In total, 53,210 adolescents were diagnosed with varicocele stage 2 and 3 prior to military service. Of 1,988 (0.13% of the total cohort) men who were diagnosed with testicular cancer during follow up, 54 (0.1%) had varicocele prior to military service while 1934(99.9%) did not, p = 0.213. The age at cancer diagnosis and the distribution of seminomas vs. non-seminomas did not differ significantly between those with and without varicocele in adolescence. In a multivariable analysis controlling for sociodemographic factors, varicocele was not associated with testicular cancer, odds ratio = 0.816 (CI 0.615-1.083).

CONCLUSIONS

Varicocele in adolecents was not found to be associated with testicular cancer in young adults.

PATIENT SUMMARY

In light of the theoretical association between varicocele and testicular cancer, we conducted this large population study. We found no association between varicocele in young adoulthoot and testicular cancer later in life. This article is protected by copyright. All rights reserved.

Obesity in late adolescence and incident type 1 diabetes in young adulthood

AIMS/HYPOTHESIS

Studies in children have reported an association between increased BMI and risk for developing type 1 diabetes, but evidence in late adolescence is limited. We studied the association between BMI in late adolescence and incident type 1 diabetes in young adulthood.

METHODS

All Israeli adolescents, ages 16-19 years, undergoing medical evaluation in preparation for mandatory military conscription between January 1996 and December 2016 were included for analysis unless they had a history of dysglycaemia. Data were linked with information about adult onset of type 1 diabetes in the Israeli National Diabetes Registry. Weight and height were measured at study entry. Cox proportional models were applied, with BMI being analysed both as a categorical and as a continuous variable.

RESULTS

There were 777 incident cases of type 1 diabetes during 15,819,750 person-years (mean age at diagnosis 25.2±3.9 years). BMI was associated with incident type 1 diabetes. In a multivariable model adjusted for age, sex and sociodemographic variables, the HRs for type 1 diabetes were 1.05 (95% CI 0.87, 1.27) for the 50th-74th BMI percentiles, 1.41 (95% CI 1.11, 1.78) for the 75th-84th BMI percentiles, 1.54 (95% CI 1.23, 1.94) for adolescents who were overweight (85th-94th percentiles), and 2.05 (95% CI 1.58, 2.66) for adolescents with obesity (≥95th percentile) (reference group: 5th-49th BMI percentiles). One increment in BMI SD was associated with a 25% greater risk for incidence of type 1 diabetes (HR 1.25, 95% CI 1.17, 1.32).

CONCLUSIONS

Excessively high BMI in otherwise healthy adolescents is associated with increased risk for incident type 1 diabetes in early adulthood.

Symptomatic Joint Hypermobility Is Associated with Low Back Pain: A National Adolescents Cohort Study

Background: Low back pain (LBP) is a widespread medical complaint affecting many people worldwide and costing billions. Studies suggest a link between LBP and joint hypermobility. This study aimed to examine the association between symptomatic joint hypermobility (SJH), LBP, and gender. Methods: Data were obtained from a medical database containing 17-year-old candidates’ records before recruitment into mandatory military service. According to the Regulations of Medical Fitness Determination, information on disability codes associated with LBP and SJH was retrieved. Results: According to this national survey, the prevalence of SJH is 0.11% (1355 cases out of 1,220,073 subjects). LBP was identified in 3.7% of the cohort (44,755 subjects). Subjects were further subdivided into LBP without objective findings (LBPWF) (3.5%) and LBP with objective findings (LBPOF) (0.2%). The association between SJH and LBP was examined: the Odds Ratio (OR) was 2.912 (p < 0.0001). The odds rations for LBPWF and LBPOF were further calculated to be 2.914 (p < 0.000) and 2.876 (p < 0.000), respectively. Subjects with SJH were almost three times more prone to LBPWF and LBPOF. Conclusion: SJH is strongly associated with LBP in young adults. Further pathophysiological research is needed.

Myopia and BMI: a nationwide study of 1.3 million adolescents

OBJECTIVE

This study analyzed the association between adolescent BMI and myopia severity.

METHODS

This cross-sectional study comprised 1,359,153 adolescents who were medically examined before mandatory military service. Mild-to-moderate and high myopia were defined based on right-eye refractive data. BMI was categorized based on the US age- and sex-matched percentiles. Logistic regression models were applied separately for women and men to estimate odds ratios (ORs) for myopia per BMI category.

RESULTS

A total of 318,712 adolescents had mild-to-moderate myopia and 23,569 had high myopia. Compared with low-normal BMI (reference group), adjusted ORs for mild-to-moderate and high myopia increased with increasing BMI status, reaching 1.39 (95% CI: 1.23-1.57) and 1.73 (95% CI: 1.19-2.51) for men with severe obesity, respectively, and 1.19 (95% CI: 1.12-1.27) and 1.38 (95% CI: 1.14-1.65) for women with mild obesity, respectively. ORs for mild-to-moderate and high myopia were also higher in men with underweight (OR = 1.20; 95% CI: 1.18-1.23 and OR = 1.39; 95% CI: 1.30-1.47) and women with underweight (OR = 1.06; 95% CI: 1.03-1.09 and OR = 1.12; 95% CI: 1.04-1.22). The overall size effect was greater for men than women (p_interaction  < 0.001), in whom the group with severe obesity did not reach statistical significance.

CONCLUSIONS

BMI was associated with myopia in a J-shaped pattern, with the size effect being greater for adolescent men than women. This study indicates that both low BMI and high BMI are associated with mild-to-moderate and severe myopia.

Glucose Intolerance in Pregnancy and Offspring Obesity in Late Adolescence

OBJECTIVE

Gestational hyperglycemia is associated with deleterious neonatal outcomes, but long-term risks for offspring obesity are less clear. We estimated the odds for offspring adolescent overweight and obesity among mothers with gestational glucose intolerance.

RESEARCH DESIGN AND METHODS

In a mother-offspring historical cohort, the Israel military conscription data set was linked to a large health maintenance organization. Included were women who were evaluated at adolescence and underwent two-step gestational diabetes screening (mean age, 31 years) with a 50-g glucose challenge test (GCT), followed by a 100-g oral glucose tolerance test (OGTT) if the result was abnormal. Glucose tolerance categories included gestational normoglycemia, abnormal GCT with normal OGTT, impaired glucose tolerance (IGT; one abnormal OGTT value), and gestational diabetes. The primary outcome was offspring overweight/obesity (BMI ≥85th percentile) at adolescence, measured prior to military conscription. Logistic regression models were applied.

RESULTS

Of 33,482 mother-offspring pairs, overweight and obesity were observed in 6,516 offspring. Across increasing categories of pregnancy glycemia, the proportions of offspring with adolescent overweight/obesity increased: normoglycemia, 19%; abnormal GCT with normal OGTT, 22%; gestational IGT, 24%; and gestational diabetes, 25% (P < 0.0001). Corresponding odds ratios after adjustment for the mother's late adolescent characteristics (sociodemographic confounders and BMI) and pregnancy age were 1.2 (95% CI 1.1-1.4), 1.3 (1.2-1.5), and 1.4 (1.3-1.6), respectively. Further adjustment for offspring birth weight percentile and sociodemographic variables did not materially change results. Associations were more pronounced with increasing obesity severity.

CONCLUSIONS

Gestational glucose intolerance, including categories not meeting the gestational diabetes threshold, was associated with increased odds for offspring overweight/obesity at late adolescence.

Personality disorders and cause-specific mortality: a nationwide study of 2 million adolescents

BACKGROUND

Personality disorders are prevalent in 6-10% of the population, but their risk for cause-specific mortality is unclear. The aim of the study was to assess the association between personality disorders diagnosed in late adolescence and all-cause as well as cause-specific (cardiovascular-related, external-related) mortality.

METHODS

We performed a longitudinal study on a historical prospective cohort based on nationwide screening prior to recruitment to the Israeli army. The study participants were 16-19-year-old persons who attended the army screening (medical and cognitive, including screening for psychiatric disorders) between 1967 and 2006. Participants were followed from 1967 till 2011.

RESULTS

The study included 2 051 606 subjects, of whom 1 229 252 (59.9%) were men and 822 354 (40.1%) were women, mean age 17.36 years. There were 55 508 (4.5%) men and 8237 (1.0%) women diagnosed with personality disorders. The adjusted hazard ratio (HRs) for coronary, stroke, cardiovascular, external-related causes and all-cause mortality among men with personality disorders were 1.34 (1.03-1.74), 1.82 (1.20-2.76), 1.45 (1.23-1.71), 1.41 (1.30-1.53) and 1.44 (1.36-1.51), respectively. The absolute rate difference for all-cause mortality was 56.07 and 13.19 per 10⁵ person-years among men and women, respectively. Among women with personality disorders, the adjusted HRs for external-related causes and all-cause mortality were 2.74 (1.87-4.00) and 2.01 (1.56-2.58). Associations were already evident within 10 years of follow-up.

CONCLUSIONS

Personality disorder in late adolescence is associated with increased risk of cardiovascular, external- and all-cause mortality. Increased cardiovascular mortality is evident before the age of 40 years and may point to the importance of lifestyle education already in youth.

The association between adolescent obesity and later gestational diabetes in military personnel: A retrospective cohort study

BACKGROUND

The association between body mass index (BMI) in adolescence and gestational diabetes mellitus (GDM) has not been completely delineated. The purpose of our study was to determine the extent by which adolescent obesity increases the risk for developing GDM later in life.

METHODS

A retrospective cohort study including all army personnel pregnancies occurring between the years 2009-2019 was conducted. Adolescent BMI of participants was available using pre-recruitment army records. GDM and other pregnancy outcomes were compared between two groups: adolescent BMI below 30 (comparison group) and that of 30 or more (exposed group). Multivariable models were adjusted for sociodemographic factors.

RESULTS

Following exclusion of cases with missing or partial glucose tests, and undocumented BMI, 6877 deliveries were included in the analysis. GDM rates were higher in the exposed group (4.9% vs. 2.9%, p value-0.09). GDM rates were twice as common in the exposed group (4.9% vs. 2.9%, p value-0.09). The multivariable model, adjusted for country of birth, socio-economic class, medical profile score, maternal age, and follow-up time, confirmed an independent association between adolescent obesity and later GDM, with an adjusted odds ratio of 2.22 (CI 1.1-4.5, p value - 0.03).

CONCLUSION

Obesity during the adolescent years is independently associated with gestational diabetes later in life.

Factors associated with resolution of childhood asthma by the age of 17: Large cohort analysis

BACKGROUND

Many children with asthma will become asymptomatic during adolescence. In this study, we evaluated factors associated with recovery from asthma by the age of 17.

METHODS

The medical records of 17-year-old conscripts to the Israeli army with asthma were compared with the records of conscripts with rigorously diagnosed resolved asthma. We assessed the association between the following parameters and asthma resolution: body mass index (BMI), recurrent rhinitis, birth season, socioeconomic level, and cognition.

RESULTS

Sixty-eight thousand and ninety conscripts with active asthma were compared to 14,695 with resolved asthma. In univariate analysis, rhinitis, overweight, underweight, higher socioeconomic level, and lower cognitive score were associated with active asthma (p < 0.001 for both sexes), but not the season of birth. In multivariate analysis, only overweight, underweight, rhinitis, and lower cognitive score (p < 0.001 for both sexes) remained significantly associated with persistence of asthma.

CONCLUSIONS

Although association does not prove causation, our finding is another reason to encourage adolescents with asthma to maintain a normal body weight. Prospective interventional studies are needed in order to decide whether changing weight to ensure BMI is within the ideal range and controlling rhinitis increases the odds of resolution of asthma in adolescence.

Attention-Deficit/Hyperactivity Disorder and Obesity: A National Study of 1.1 Million Israeli Adolescents

PURPOSE

The incidences of obesity and attention-deficit/hyperactivity disorder (ADHD) have increased in parallel over recent decades. We assessed the association between obesity and ADHD in a national sample of adolescents.

METHOD

In a nationwide population-based study of 1 118 315 adolescents (57% males; mean age 17 years), risks of obesity were compared between individuals with severe and mild ADHD and those without ADHD. Diagnoses of ADHD were confirmed by specialists in either neurology or psychiatry. Adolescents requiring regular and continuous treatment with stimulants with no improvement of symptoms under treatment were classified as having severe ADHD; data were available from 2004 to 2019. During 2015 to 2019, the diagnosis of ADHD was defined, and 65 118 (16.76%) of 388 543 adolescents with mild symptoms who required medications only for learning or who used stimulants irregularly were defined as having mild ADHD.

RESULTS

The prevalence of severe and mild ADHD was 0.3% and 20.1%, respectively. Obesity was more prevalent among adolescents with severe ADHD than among those without ADHD (13.5% vs 7.5%). In the mild ADHD group 12.6% of males and 8.4% of females were diagnosed with obesity compared to 9.7% and 6.4%, respectively, in the non-ADHD group. The adjusted odds of severe ADHD for males and females with obesity were 1.77 (1.56-2.02) and 2.09 (1.63-2.66) times the odds for males and females with low-normal body mass index, respectively, and 1.42 (1.37-1.48) and 1.42 (1.34-1.50) for males and females with mild ADHD, respectively. The elevated risk persisted in several sensitivity analyses.

CONCLUSIONS

Both adolescents with severe and mild ADHD are at increased risk for obesity.

Adolescent Blood Pressure and the Risk for Early Kidney Damage in Young Adulthood

BACKGROUND

Recent guidelines classified blood pressure above 130/80 mm Hg as hypertension. However, outcome data were lacking.

OBJECTIVE

To determine the association between blood pressure in adolescence and the risk for early kidney damage in young adulthood.

METHODS

In this nationwide cohort study, we included 629 168 adolescents aged 16 to 20 who underwent medical examinations before mandatory military service in Israel. We excluded 30 466 adolescents with kidney pathology, hypertension, or missing blood pressure or anthropometric data at study entry. Blood pressure measurements at study entry were categorized according to the Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents: group A (<120/<80 mm Hg; Reference group), group B (120/<80-129/<80 mm Hg), group C (130/80-139/89 mm Hg), and group D (≥140/90 mm Hg). Early kidney damage in young adulthood was defined as albuminuria of ≥30 mg/g with an estimated glomerular filtration rate of 60 mL/(min·1.73 m²) or over.

RESULTS

Of 598 702 adolescents (54% men), 2004 (0.3%) developed early kidney damage during a mean follow-up of 15.1 (7.2) years. The adjusted hazard ratios for early kidney damage in blood pressure group C were 1.17 (1.03-1.32) and 1.51 (1.22-1.86) among adolescents with lean (body mass index <85th percentile) and high body mass index (body mass index ≥85th percentile), respectively. Corresponding hazard ratios for kidney disease in group D were 1.49 (1.15-1.93) and 1.79 (1.35-2.38) among adolescents with lean and high body mass index, respectively.

CONCLUSIONS

Blood pressure of ≥130/80 mm Hg was associated with early kidney damage in young adulthood, especially in adolescents with overweight and obesity.

Myopia and Early-Onset Type 2 Diabetes: A Nationwide Cohort Study

CONTEXT

A correlation between myopia and insulin resistance has been suggested.

OBJECTIVE

We investigated the association between myopia in adolescence and type 2 diabetes (T2D) incidence in young adulthood.

METHODS

This population-based, retrospective, cohort study comprised 1 329 705 adolescents (579 543 women, 43.6%) aged 16 to 19 years, who were medically examined before mandatory military service during 1993 to 2012, and whose data were linked to the Israel National Diabetes Registry. Myopia was defined based on right-eye refractive data. Cox proportional models were applied, separately for women and men, to estimate hazard ratios (HRs) for T2D incidence per person-years of follow-up.

RESULTS

There was an interaction between myopia and sex with T2D (P < .001). For women, T2D incidence rates (per 100 000 person-years) were 16.6, 19.2, and 25.1 for those without myopia, and with mild-to-moderate and high myopia, respectively. These corresponded to HRs of 1.29 (95% CI, 1.14-1.45) and 1.63 (1.21-2.18) for women with mild-to-moderate and high myopia, respectively, compared to those without myopia, after adjustment for age at study entry, birth year, adolescent body mass index, cognitive performance, socioeconomic status, and immigration status. Results persisted in extensive sensitivity and subgroup analyses. When managed as a continuous variable, every 1-diopter lower spherical equivalent yielded a 6.5% higher adjusted HR for T2D incidence (P = .003). There was no significant association among men.

CONCLUSION

For women, myopia in adolescence was associated with a significantly increased risk for incident T2D in young adulthood, in a severity-dependent manner. This finding may support the role of insulin resistance in myopia pathogenesis.

The opposing trends of body mass index and blood pressure during 1977-2020; nationwide registry of 2.8 million male and female adolescents

Background

Elevated blood pressure among adolescents has been shown to be associated with future adverse cardiovascular outcomes and early onset diabetes. Most data regarding systolic and diastolic blood pressure trends are based on surveys of selected populations within 10–20-year periods. The goal of this study was to characterize the secular trend of blood pressure given the rising prevalence of adolescent obesity.

Methods

This nationwide population-based study included 2,785,515 Israeli adolescents (41.6% females, mean age 17.4 years) who were medically evaluated and whose weight, height and blood pressure were measured, prior to mandatory military service between 1977 and 2020. The study period was divided into 5-year intervals. Linear regression models were used to describe the P for trend along the time intervals. Analysis of covariance was used to calculate means of blood pressure adjusted for body mass index.

Results

During the study period, the mean body mass index increased by 2.1 and 1.6 kg/m² in males and females, respectively (P for trend  < 0.001 in both sexes). The mean diastolic blood pressure decreased by 3.6 mmHg in males and by 2.9 mmHg in females (P  < 0.001 in both sexes). The mean systolic blood pressure increased by 1.6 mmHg in males and decreased by 1.9 mmHg in females. These trends were also consistent when blood pressure values were adjusted to body mass index.

Conclusion

Despite the increase in body mass index over the last four decades, diastolic blood pressure decreased in both sexes while systolic blood pressure increased slightly in males and decreased in females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01433-0.

Adolescent body mass index and changes in pre-pregnancy body mass index in relation to risk of gestational diabetes

BACKGROUND

Pregestational excessive body mass index (BMI) is linked to an increased risk for gestational diabetes mellitus (GDM), but less is known on the effect of adolescent BMI on GDM occurrence. The study aimed to investigate possible associations of adolescent BMI and changes in BMI experienced before first pregnancy, with gestational diabetes risk.

METHODS

This retrospective study was based on linkage of a military screening database of adolescent health status (Israel Defence Forces) including measured height and weight, with medical records (Maccabi Healthcare Services, MHS) of a state-mandated health provider. The latter covers about 25% of the Israeli population; about 90% of pregnant women undergo screening by the two-step Carpenter-Coustan method. Adolescent BMI was categorized according to Center of Disease Control and Prevention percentiles. Only first documented pregnanies were analyzed and GDM was the outcome.

FINDINGS

Of 190,905 nulliparous women, 10,265 (5.4%) developed GDM. Incidence proportions of GDM were 5.1%, 6.1%, 7.3%, and 8.9% among women with adolescent normal BMI, underweight, overweight, and obesity (p<0.001), respectively. In models that accounted for age at pregnancy, birth year, and sociodemographic variables, the adjusted odd ratios (aORs) for developing GDM were: 1.2 (95%CI, 1.1-1.3), 1.5 (1.4-1.6), and 1.9 (1.7-2.1) for adolescent underweight, overweight, and obesity (reference group, normal BMI). Adolescent BMI tracked with BMI notes in the pre-pregnancy period (r=63%). Resuming normal pre-pregnancy BMI from overweight or obesity in adolescence diminished GDM risk, but this diminished risk was not observed among those who returned to a normal per-pre-pregnancy BMI from being underweight in adolescence. Sustained overweight or obesity conferred an aOR for developing GDM of 2.5 (2.2-2.7); weight gain from adolescent underweight and normal BMI to pre-pregnancy excessive BMI conferred aORs of 3.1 (1.6-6.2) and 2.6 (2.2-2.7), respectively.

INTERPRETATION

Change in BMI status from adolescence to pre-pregnancy may contribute to GDM risk. Identifying at-risk populations is important for early preventive interventions.

FUNDING

None.

Asthma in Youth and Early-onset Type 2 Diabetes: A Nationwide Study of 1.72 Million Israeli Adolescents

BACKGROUND

The prevalence of both asthma and early-onset diabetes is on the rise; however, the association between them remains unclear. We examined a possible association of asthma at adolescence with type 2 diabetes in young adulthood.

METHODS

This is a nationwide, population-based study of 1 718 541 Israeli adolescents (57% males; mean age 17.3 years; range 16-19 years), examined before compulsory military service between 1992 and 2016, with data linked to the Israeli National Diabetes Registry. Asthma diagnosis and severity were determined by a board-certified pulmonologist and based on spirometry tests.

RESULTS

Type 2 diabetes developed in 58/9090 (0.64%), 507/97 059 (0.52%), 114/23 332 (0.49%), and 7095/1 589 060 (0.44%) persons with moderate-to-severe, mild, inactive, and no history of asthma, respectively, during a mean follow-up >13 years. The respective odds ratios (ORs) were 1.33 (95% CI, 1.02-1.74), 1.17 (1.06-1.28), and 1.09 (0.9-1.31), considering those without asthma history as the reference, in a model adjusted for birth year, sex, body mass index, and other sociodemographic variables. The association persisted when the analysis accounted for coexisting morbidities, and when persons without asthma, individually matched by age, sex, birth year, and body mass index were the reference. Both mild and moderate-to-severe asthma were associated with type 2 diabetes before age 35 years: ORs 1.18 (1.05-1.34) and 1.44 (1.05-2.00), respectively. The strength of the association was accentuated over time. The effect was unchanged when adjusted for oral and inhaled glucocorticoid use.

CONCLUSION

Adolescents with active asthma have higher risk to develop type 2 diabetes. This seems related to disease severity, independent of adolescent obesity status, apparent before age 35 years, and more pronounced in recent years.

Adolescent cognitive function and incident early-onset type 2 diabetes

BACKGROUND

Cognitive function among apparently healthy adolescents has been associated with cardiovascular morbidity and mortality. We examined the relationship between global and subdomain cognitive scores in adolescence and early-onset type 2 diabetes (T2D) in men and women.

METHODS

A nationwide, population-based study of 971,677 Israeli born adolescents (56% men; mean age 17.4 years) who were medically examined and their cognitive performance was assessed before compulsory military service during 1992-2010. Data included global and subdomain cognitive Z-scores (problem-solving, verbal abstraction and categorization, verbal comprehension, and mathematical abilities). Data were linked to the Israeli National Diabetes Registry. The relations between global and subdomain scores and incident T2D was determined using Cox proportional hazard models and logistic regression models. Analyses were conducted separately for men and women.

FINDINGS

During 16,095,122 person-years, 3,570 individuals developed T2D. After adjustment, those in the low compared to the high quintile of global cognitive Z-score had the highest risk for T2D; HR 2.46, (95% CI 2.10-2.88) for men and 2.33 (95% CI 1.88-2.89) for women. A one-unit lower global cognitive Z-score was associated with 1.41 (95% CI 1.34-1.48) and 1.46 (95% CI 1.36-1.56) increased risks for men and women, respectively. The relationship was noted for the cognitive subdomains scores as well as for the global cognitive score, with no heterogeneity across cognitive subdomains.

INTERPRETATION

This large nationally representative cohort suggests relationship between global, as well as subdomain cognitive scores in late adolescence, and incident early onset T2D in both sexes, which was independent of socioeconomic status.

Adolescent Thyroid Disorders and Risk for Type 2 Diabetes in Young Adulthood

CONTEXT

Thyroid hormones play a key role in systemic metabolism, yet the relationship between thyroid dysfunction and risk for type 2 diabetes is unclear.

OBJECTIVE

To assess type 2 diabetes risk in adulthood among adolescents with thyroid disorders.

DESIGN AND SETTING

A nationwide, population-based study of Israeli adolescents who were examined before military recruitment during 1988 to 2007 and were followed until December 31, 2016.

PARTICIPANTS

1 382 560 adolescents (mean age 17.3 years).

INTERVENTIONS

The diagnosis of thyroid disorders was based on recent thyroid function tests. Data were linked to the Israeli National Diabetes Registry. Cox proportional hazard models were applied.

MAIN OUTCOME MEASURES

Type 2 diabetes incidence.

RESULTS

During a mean follow-up of 18.5 years, 1.12% (69 of 6,152) of adolescents with thyroid disorders were diagnosed with type 2 diabetes vs 0.77% of adolescents without thyroid disorders. The hazard ratio (HR) for type 2 diabetes was 2.3 (95% CI, 1.8-2.9) among those with thyroid disorders, after adjustment for sex, birth-year, body mass index, and sociodemographic confounders. The increased diabetes risk was observed in both men and women, with the presence or absence of obesity, and in the absence of other health conditions and was associated with different types of thyroid disorders. It was also similar when the outcome was defined as type 2 diabetes diagnosed at or before the age of 30 years (HR 2.3, 95% CI, 1.5-3.5).

CONCLUSIONS

Thyroid disorders diagnosed in adolescence are a risk factor for early-onset type 2 diabetes in both men and women.

Body Mass Index in 1.9 Million Adolescents and Stroke in Young Adulthood

[Figure: see text].

Stuttering and Incident Type 2 Diabetes: A Population-Based Study of 2.2 Million Adolescents

PURPOSE

To investigate the association between stuttering in adolescence and incident type 2 diabetes in young adulthood.

METHODS

This nationwide population-based study included 2 193 855 adolescents of age 16 to 20 years who were assessed for military service between 1980 and 2013. Diagnoses of stuttering in adolescence were confirmed by a speech-language pathologist. Diabetes status for each individual as of December 31, 2016, was determined by linkage to the Israeli National Diabetes Registry. Relationships were analyzed using regression models adjusted for socioeconomic variables, cognitive performance, coexisting morbidities, and adolescent body mass index.

RESULTS

Analysis was stratified by sex (Pinteraction = 0.035). Of the 4443 (0.4%) adolescent men with stuttering, 162 (3.7%) developed type 2 diabetes, compared with 25 678 (2.1%) men without stuttering (adjusted odds ratio [OR] 1.3; 95% CI, 1.1-1.6). This relationship persisted when unaffected brothers of men with stuttering were used as the reference group (adjusted OR = 1.5; 95% CI, 1.01-2.2), or when the analysis included only adolescents with unimpaired health at baseline (adjusted OR = 1.4; 95% CI, 1.1-1.7). The association was stronger in later birth cohorts, with an adjusted OR of 2.4 (1.4-4.1) for cases of type 2 diabetes before age 40. Of the 503 (0.1%) adolescent women with stuttering 7 (1.4%) developed type 2 diabetes, compared with 10 139 (1.1%) women without stuttering (OR = 2.03; 95% CI, 0.48-2.20).

CONCLUSIONS

Adolescent stuttering is associated with an increased risk for early-onset type 2 diabetes among men.

Childhood Cancer and the Risk of ESKD

BACKGROUND

Increasing cancer incidence among children alongside improved treatments has resulted in a growing number of pediatric cancer survivors. Despite childhood cancer survivors' exposure to various factors that compromise kidney function, few studies have investigated the association between childhood cancer and future kidney disease.

METHODS

To assess the risk of ESKD among childhood cancer survivors, we conducted a nationwide, population-based, retrospective cohort study that encompassed all Israeli adolescents evaluated for mandatory military service from 1967 to 1997. After obtaining detailed histories, we divided the cohort into three groups: participants without a history of tumors, those with a history of a benign tumor (nonmalignant tumor with functional impairment), and those with a history of malignancy (excluding kidney cancer). This database was linked to the Israeli ESKD registry to identify incident ESKD cases. We used Cox proportional hazards models to estimate the hazard ratio (HR) of ESKD.

RESULTS

Of the 1,468,600 participants in the cohort, 1,444,345 had no history of tumors, 23,282 had a history of a benign tumor, and 973 had a history of malignancy. During a mean follow-up of 30.3 years, 2416 (0.2%) participants without a history of tumors developed ESKD. Although a history of benign tumors was not associated with an increased ESKD risk, participants with a history of malignancy exhibited a substantially elevated risk for ESKD compared with participants lacking a history of tumors, after controlling for age, sex, enrollment period, and paternal origin (adjusted HR, 3.2; 95% confidence interval, 1.3 to 7.7).

CONCLUSIONS

Childhood cancer is associated with an increased risk for ESKD, suggesting the need for tighter and longer nephrological follow-up.

Congenital Anomalies of the Kidney and Urinary Tract and Adulthood risk of Urinary Tract Cancer

Introduction

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common kidney diseases in childhood. Alterations in genes governing nephrogenesis may cause CAKUT, and in some cases may contribute to development of urinary tract (UT) tumors later in life. We aimed to assess the association between CAKUT and UT cancer in adulthood.

Methods

We conducted a population-based historical cohort study encompassing 1,510,042 recruits to the Israeli army between 1967 and 1997. CAKUT exposure was determined by army medical coding of CAKUT in childhood. Incidence of UT cancer (kidney, ureter, or bladder) was available through record linkage with the Israeli Cancer Registry. Recruits were followed from the prerecruitment assessment until cancer diagnosis, death, or study termination, in 2012. Cox proportional hazards models were constructed to estimate the hazard ratios (HRs) for UT cancer in participants with vs. without CAKUT.

Results

During a mean follow-up of 30.4 years, 2959 participants (2573 men and 386 women) developed UT cancer. Men with CAKUT exhibited an increased risk of UT cancer compared with men without CAKUT, yielding an adjusted HR of 1.98 (95% confidence interval [CI] 1.03-3.82). Among women CAKUT was associated with a HR of 5.88 (95% CI 2.19-15.76). Notably, upon stratification according to age of cancer diagnosis, the association between CAKUT and UT cancer was statistically significant only before 45 years of age in women and only after 45 years of age in men.

Conclusion

CAKUT is associated with a significantly increased risk of UT cancer, although the incidence and absolute risk remained quite low.

Adolescent Nonalcoholic Fatty Liver Disease and Type 2 Diabetes in Young Adulthood

CONTEXT

The long-term risk of type 2 diabetes in adolescents with nonalcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVE

To assess type 2 diabetes risk among adolescents with NAFLD.

DESIGN AND SETTING

A nationwide, population-based study of Israeli adolescents who were examined before military service during 1997-2011 and were followed until December 31, 2016.

PARTICIPANTS

A total of 1 025 796 normoglycemic adolescents were included.

INTERVENTIONS

Biopsy or radiographic tests were prerequisite for NAFLD diagnosis. Data were linked to the Israeli National Diabetes Registry.

MAIN OUTCOME MEASURES

Type 2 diabetes incidence.

RESULTS

During a mean follow-up of 13.3 years, 12 of 633 adolescents with NAFLD (1.9%; all with high body mass index [BMI] at baseline) were diagnosed with type 2 diabetes compared with 2917 (0.3%) adolescents without NAFLD. The hazard ratio (HR) for type 2 diabetes was 2.59 (95% confidence interval [CI], 1.47-4.58) for the NAFLD vs. the non-NAFLD group after adjustment for BMI and sociodemographic confounders. The elevated risk persisted in several sensitivity analyses. These included an analysis of persons without other metabolic comorbidities (adjusted HR, 2.75 [95% CI, 1.48-5.14]) and of persons with high BMI; and an analysis whose outcome was type 2 diabetes by age 30 years (adjusted HR, 2.14 [95% CI, 1.02-4.52]). The results remained significant when a sex-, birth year-, and BMI-matched control group was the reference (adjusted HR, 2.98 [95% CI, 1.54-5.74]).

CONCLUSIONS

Among normoglycemic adolescents, NAFLD was associated with an increased adjusted risk for type 2 diabetes, which may be apparent before age 30 years.

Socioeconomic inequalities and severe obesity-Sex differences in a nationwide study of 1.12 million Israeli adolescents

INTRODUCTION

In a nationwide population of adolescents, we investigated the sex-specific association of socioeconomic position (SEP) with severe obesity, and trends over time.

METHODS

The cohort comprises all Israeli adolescents (mean ± SD age 17.3 ± 0.5 years) who were medically examined, before mandatory military service during 2000 to 2015. Of 1 120 362 adolescents, 239 816 (21.4%) were classified with overweight or with obesity classes I to III using the International Obesity Task Force criteria. Data were compared between 2000 to 2009 and 2010 to 2015.

RESULTS

Considering more advantaged residential SEP as the reference group, the respective odds ratios (ORs ± 95%CI) of less advantaged SEP for obesity classes I to III in 2010 to 2015 were 1.48 (1.40-1.56), 1.66 (1.51-1.83), and 1.73 (1.45-2.08) for males; and 1.72 (1.60-1.84), 1.89 (1.66-2.15), and 2.62 (2.04-3.37) for females. All point estimates were higher than in the preceding decade. Considering female inductees from the more advantaged SEP as the reference group, ORs were higher for males in the more advantaged SEP group, for overweight, 1.31 (1.27-1.36); class I obesity, 1.29 (1.20-1.38); class II obesity, 1.34 (1.18-1.53); and class III obesity, 1.60 (1.24-2.07). Similarly, in the less and medium advantaged SEP groups, increased ORs for males compared with females were observed in all obesity groups. Results persisted using United States Centers for Disease Control and Prevention growth charts.

CONCLUSIONS

Adolescents with less rather than more advantaged residential SEP are at greater risk of severe obesity. Adolescent males, of all residential SEP groups had higher odds than females for all classes of obesity.

The association between late-adolescent smoking and long-term mortality: a dose-response relationship

Introduction

Tobacco smoking has detrimental medical effects. However, whether late-adolescence tobacco smoking increases early mortality risk is unclear. The aim of our study was to determine the association between tobacco smoking among Israeli adolescents and mortality in young adulthood.

Methods

The Israeli Defense Forces (IDF) health survey enrolls annually random sample of 3–5% of IDF recruits who voluntarily report lifestyle and tobacco consumption habits (up to 10 cigarettes a day were defined as light smokers, 10–20 cigarettes a day and above 20 cigarettes a day as medium and heavy smokers respectively). Medical and sociodemographic variables (education, residential socioeconomic status, country of birth or origin) were included. Included in this study were 62,134 soldiers (56% men; average age 17.3 years) who enrolled in the study between 1981 and 2006. Data from the Israeli Ministry of Interior was obtained by linkage. Follow-up terminated at the earliest of December 31st 2018 or death. Cox proportional hazard models were applied.

Results

There were 42,013 (67.6%) never smokers, 2,108 (3.4%) past smokers, 6,886 (11.1%) light, 9,880 (15.9%) medium and 1,247 (2%) heavy smokers. During 1,348,517 person-years, 548 deaths were recorded (327 were never smokers, and 18,54,121 and 28 were past, light, medium and heavy smokers, respectively; mean age 31.3 years). The hazard ratios for all-cause mortality were 0.98 (0.61–1.58), 1.02 (0.76–1.36), 1.32 (1.06–1.64) and 1.53 (1.03–2.30) for past smokers, light, medium and heavy smokers, respectively, after adjustment for age, gender, BMI, enrollment year, education and intelligence score. There was no sex-specific association and mortality risk among heavy smokers persisted even when the outcome was set as death by the age of 30 years.

Conclusion

Late-adolescent smoking is associated with long-term all-cause mortality. A dose-response relationship was demonstrated between number of cigarettes consumed at the age of 17 and the future risk of death.

Kaplan-Meier Plot

Funding Acknowledgement

Type of funding source: None

Adolescent BMI and early-onset type 2 diabetes among Ethiopian immigrants and their descendants: a nationwide study

Background

We assessed in a nationwide cohort the association between adolescent BMI and early-onset (< 40 years) type 2 diabetes among Israelis of Ethiopian origin.

Methods

Normoglycemic adolescents (range 16–20 years old), including 93,806 native Israelis (≥ 3rd generation in Israel) and 27,684 Israelis of Ethiopian origin, were medically assessed for military service between 1996 and 2011. Weight and height were measured. Data were linked to the Israeli National Diabetes Registry. Incident type 2 diabetes by December 31, 2016 was the outcome. Cox regression models stratified by sex and BMI categories were applied.

Results

226 (0.29%) men and 79 (0.18%) women developed diabetes during 992,980 and 530,814 person-years follow-up, respectively, at a mean age of 30.4 and 27.4 years, respectively. Among native Israeli men with normal and high (overweight and obese) BMI, diabetes incidence was 9.5 and 62.0 (per 10⁵ person-years), respectively. The respective incidences were 46.9 and 112.3 among men of Ethiopian origin. After adjustment for sociodemographic confounders, the hazard ratios for type 2 diabetes among Ethiopian men with normal and high BMI were 3.4 (2.3–5.1) and 15.8 (8.3–30.3) respectively, compared to third-generation Israelis with normal BMI. When this analysis was limited to Israeli-born Ethiopian men, the hazard ratios were 4.4 (1.7–11.4) and 29.1 (12.9–70.6), respectively. Results persisted when immigrants of other white Caucasian origin were the reference; and among women with normal, but not high, BMI.

Conclusions

Ethiopian origin is a risk factor for early-onset type 2 diabetes among young men at any BMI, and may require selective interventions.

Acute pyelonephritis in children and the risk of end-stage kidney disease

BACKGROUND

Pyelonephritis is the most common serious bacterial infection during childhood. The long-term importance of kidney scarring is unclear.

OBJECTIVE

To assess the risk of end-stage kidney disease (ESKD) in adolescents and young adults with history of pyelonephritis.

STUDY DESIGN

A nationwide, population-based, historical cohort study, including 1,509,902 persons (62% male) examined for military service between 1967 and 1997. Participants with a history of pyelonephritis were sub-grouped according to presence of kidney scarring and baseline kidney function. Data were linked to the Israeli ESKD registry to identify incident ESKD cases. Cox proportional hazards models were used to estimate the hazard ratio (HR) of treated ESKD (dialysis or kidney transplant).

RESULTS

Pyelonephritis was diagnosed in 6979 participants (0.46%). 6479 had normal kidney function and no evidence of kidney scarring, 400 had normal kidney function with evidence of scarring, and 100 demonstrated reduced baseline kidney function. Treated ESKD developed in 2352 individuals (0.2%) without history of pyelonephritis, 58 individuals (0.9%) with normal kidney function, history of pyelonephritis and no kidney scarring, 14 individuals (3.5%) with normal kidney function, history of pyelonephritis and kidney scarring, and 23 individuals (23.0%) with history of pyelonephritis and reduced baseline kidney function, yielding HR of 3.3, 34.8 and 43.2, respectively, controlling for age, gender, paternal origin, enrollment year, body mass index, and blood pressure, and accounting for death as a competing risk.

CONCLUSION

History of pyelonephritis was associated with significantly increased risk of treated ESKD, particularly when associated with kidney scarring or reduced baseline kidney function.

Adolescent Obesity and Early-Onset Type 2 Diabetes

OBJECTIVE

Type 2 diabetes (T2D) is increasingly diagnosed at younger ages. We investigated the association of adolescent obesity with incident T2D at early adulthood.

RESEARCH DESIGN AND METHODS

A nationwide, population-based study evaluated 1,462,362 adolescents (59% men, mean age 17.4 years) during 1996-2016. Data were linked to the Israeli National Diabetes Registry. Weight and height were measured at study entry. Cox proportional models were applied.

RESULTS

During 15,810,751 person-years, 2,177 people (69% men) developed T2D (mean age at diagnosis 27 years). There was an interaction among BMI, sex, and incident T2D (P _interaction = 0.023). In a model adjusted for sociodemographic variables, the hazard ratios for diabetes diagnosis were 1.7 (95% CI 1.4-2.0), 2.8 (2.3-3.5), 5.8 (4.9-6.9), 13.4 (11.5-15.7), and 25.8 (21.0-31.6) among men in the 50th-74th percentile, 75th-84th percentile, overweight, mild obesity, and severe obesity groups, respectively, and 2.2 (1.6-2.9), 3.4 (2.5-4.6), 10.6 (8.3-13.6), 21.1 (16.0-27.8), and 44.7 (32.4-61.5), respectively, in women. An inverse graded relationship was observed between baseline BMI and mean age of T2D diagnosis: 27.8 and 25.9 years among men and women with severe obesity, respectively, and 29.5 and 28.5 years among low-normal BMI (5th-49th percentile; reference), respectively. The projected fractions of adult-onset T2D that were attributed to high BMI (≥85th percentile) at adolescence were 56.9% (53.8-59.9%) and 61.1% (56.8-65.2%) in men and women, respectively.

CONCLUSIONS

Severe obesity significantly increases the risk for incidence of T2D in early adulthood in both sexes. The rise in adolescent severe obesity is likely to increase diabetes incidence in young adults in coming decades.

Does birth season influence the odds for asthma? Large cohort analysis

BACKGROUND AND OBJECTIVE

Few studies have examined the possibility of a link between birth season and the risk for asthma. Those studies that mainly focused on young children, reached different conclusions regarding both the existence of such a link and the season with the highest risk. The purpose of this study was to reinvestigate the relationship between birth season and asthma in a very large cohort, larger than in all previous studies, focusing on adolescents.

METHODS

The medical records of consecutive 17-year-old conscripts, born between 1978 and 1999, undergoing medical evaluation before their military service, were reviewed. The prevalence of asthma among conscripts was calculated according to the season of birth.

RESULTS

Data from 6 26 460 males and 4 54 104 females were collected. Asthma prevalence was 6.6% of the males and 5.8% of the females. Asthma prevalence was highest among those born in the summer and was approximately 9% higher in women and 6% higher in men than those born in the winter. Those born in the winter had the lowest prevalence of asthma. June was the birth month with the highest prevalence of asthma in both genders together with September among males.

CONCLUSIONS

Being born in the summer, especially in June, is associated with an increased risk of asthma compared with a winter birth among Israeli army conscripts. Further research is required to determine the impact of the season of birth on the risk of asthma in higher risk populations.

Adolescent obesity and midlife cancer risk: a population-based cohort study of 2·3 million adolescents in Israel

BACKGROUND

Obesity has been established as a causal factor for several types of cancer, and adolescent obesity is increasing worldwide. We examined associations between measured body-mass index (BMI) at age 17 years and cancer incidence, and with mortality among those who developed cancer.

METHODS

In a nationwide, population-based cohort of adolescents, height and weight were measured at pre-recruitment mandatory medical examination during 1967-2010. BMI was classified according to US Center for Disease Control and Prevention percentiles. We applied Cox proportional hazard models to estimate the hazard ratios (HRs) and 95% CIs for incident cases of cancer using the 5th-49th BMI percentile group as a reference. The primary outcome was any cancer diagnosis between Jan 1, 1967, and Dec 31, 2012, as recorded in the Israeli National Cancer Registry. Participants with a diagnosis of cancer at baseline (before military recruitment assessment) were excluded from this analysis. The secondary outcome of this study was all-cause mortality among cohort members who had cancer, between Jan 1, 1967, and Dec 31, 2017.

FINDINGS

Of the 2 458 170 participants examined between Jan 1, 1967, and Dec 31, 2010, 160 040 were excluded. 2 298 130 participants of which 928 110 were women and 1 370 020 were men. During 29 542 735 person-years of follow-up in men, 26 353 incident cases of cancer were recorded and in 18 044 863 person-years of follow-up in women, 29 488 incident cases of cancer were recorded. Cancer incidence increased gradually across BMI percentiles. The adjusted HR was 1·26 (95% CI 1·18-1·35) among men with adolescent obesity. Among women, we found no association between obesity and overall cancer, driven by inverse associations of obesity with cervical and breast cancers. When these cancers were excluded, the adjusted HR for cancer was 1·27 (1·13-1·44) among women with adolescent obesity. In both sexes, high BMI (≥85th percentile) was associated with an increased cancer risk after 10 years. This association was accentuated in the late period of the cohort versus the early period of the cohort. BMI was positively associated with a higher risk of mortality. The projected population attributable risk for high BMI was 5·1% (4·2-6·1) for men and 5·7% (4·2-7·3) for women.

INTERPRETATION

The increasing prevalence of adolescent obesity and the possible association between adolescent BMI and cancer incidence might increase the future burden of obesity-related cancers. BMI among adolescents could constitute an important intervention target for cancer prevention.

FUNDING

None.

Childhood Pancreatitis and Risk for Incident Diabetes in Adulthood

OBJECTIVE

The relationship between acute pancreatitis and incident diabetes is unclear. We assessed whether a resolved single event of acute pancreatitis in childhood was associated with incident diabetes in adulthood.

RESEARCH DESIGN AND METHODS

A nationwide, population-based study of 1,802,110 Israeli adolescents (mean age 17.4 years [range 16-20]) who were examined before compulsory military service between 1979 and 2008 and whose data were linked to the Israeli National Diabetes Registry (INDR). Resolved pancreatitis was defined as a history of a single event of acute pancreatitis with normal pancreatic function at enrollment. Logistic regression analysis was applied.

RESULTS

Incident diabetes developed in 4.6% of subjects with resolved pancreatitis (13 of 281; none of these cases were identified as type 1 diabetes) and 2.5% among the unexposed group (44,463 of 1,801,716). Resolved acute pancreatitis was associated with incident diabetes with an odds ratio (OR) of 2.23 (95% CI 1.25-3.98) with adjustment for age, sex, and birth year. Findings persisted after further adjustments for baseline BMI and sociodemographic confounders (OR 2.10 [95% CI 1.15-3.84]). Childhood pancreatitis was associated with a diagnosis of diabetes at a younger age, with 92% of diabetes case subjects diagnosed before 40 years of age compared with 47% in the unexposed group (P = 0.002). The association accentuated when the study sample was limited to individuals of unimpaired health or normal BMI at baseline.

CONCLUSIONS

A history of acute pancreatitis in childhood with normal pancreatic function in late adolescence is a risk factor for incident type 2 diabetes, especially at young adulthood.

Impact of Immigration on Body Mass Index and Blood Pressure Among Adolescent Males and Females: A Nationwide Study

Immigration from one cultural milieu to another has been associated with a greater risk for incident cardio-metabolic morbidity among adults. In this nationwide, population-based, cross-sectional study of data recorded from 1992 to 2016, we assessed the association between body mass index and blood pressure levels among adolescent immigrants, aged 16 to 19 years, of Ethiopian origin, and their secular trend of overweight and obesity. Adolescents of Ethiopian origin were classified as Israeli-born (n=16 153) or immigrants (N=23 487), with stratification by age at immigration. Adolescents whose fathers were at least 3 generations in Israel (n=277 789) served as a comparative group. Hypertensive-range blood pressure values adjusted for age, sex, and height served as outcome. Among adolescents of Ethiopian origin, overweight and obesity (body mass index ≥85th percentile), increased by 2.5 and 4-fold in males and females, respectively, during the study period, compared with a 1.5-fold increase among native Israeli-born males and females. The odds for hypertensive-range measurements increased with the length of residence in Israel: 7.3%, 10.6%, and 14.4% among males who immigrated at ages 12 to 19, 6 to 11.9, and 0 to 5.9 years, respectively; and 11.5%, 16.7%, and 19.3%, respectively, among females. Israeli-born Ethiopians had a significantly higher risk for hypertensive-range measurements at any body mass index level compared with native Israeli-born examinees, after adjusting for sociodemographic factors and health status. In conclusion, among Ethiopian Israeli adolescents, abnormal blood pressure correlates directly with the time-lapse since immigration. Immigrant populations require targeted surveillance and appropriate intervention.

Coronal Knee Malalignment in Young Adults and Its Link to Body Measures

Our aim was to report the prevalence of knee varus-valgus malalignment (KVVM) and its association with body mass index (BMI) and body height in a healthy and fit young adult population. Information on the disability codes associated with KVVM according to the Regulations of Medical Fitness Determination was retrieved from a medical database containing records of 17-year-old males and females before their recruitment into mandatory military service. Logistic regression models assessed the association between the BMI and body height to KVVM. The study cohort included 821,381 subjects (460,674 males and 360,707 females). The prevalence of KVVM was 0.9% in males and 0.6% for females. Under/overweight subjects were associated with higher prevalence of KVVM. The odds ratios (ORs) had a "J" curve pattern, increasing for underweight males and females, and even more so for above-normal BMIs (for obese males and for both overweight and obese females). The strongest association was between obese females and KVVM: an obese female had an OR of 22.864 (confidence interval [CI] = 20.683-25.725, p < 0.001) to have KVVM and an obese male had an OR of 4.483 (CI = 4.158-4.833 p < 0.001). When the BMI was analyzed as a continuous variable, each increase in one BMI unit was associated with an increase in OR of 7.6% for males and 24.1% for females. There is a strong association between BMI and KVVM in both underweight and overweight young adults. KVVM is more common in males, but most strongly associated with overweight and obese females.This is a Level III, case-control study.

Adolescent overweight and obesity and the risk for pancreatic cancer among men and women: a nationwide study of 1.79 million Israeli adolescents

BACKGROUND

There is growing concern regarding the impact of adolescent obesity on adult health. The objective of this study was to evaluate the association between body mass index (BMI) in late adolescence and the incidence of pancreatic cancer during adulthood.

METHODS

The authors analyzed a cohort of 1087,358 Israeli Jewish men and 707,212 Jewish women who underwent a compulsory physical examination between ages 16 and 19 years from 1967 to 2002. Pancreatic cancer incidence through December 31, 2012 was identified by linkage to the national cancer registry. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) for pancreatic cancer according to the US Centers for Disease Control and Prevention (CDC) BMI percentiles at baseline.

RESULTS

Over a median 23 year follow-up, 551 incident cases of pancreatic cancer cases occurred (423 men; 128 women). Compared with normal weight (5th to-<85th percentile), obesity (≥95th percentile) was associated with an increased risk of cancer among both men (HR, 3.67; 95% confidence interval [CI], 2.52-5.34) and women (HR, 4.07; 95% CI, 1.78-9.29). Among men, compared with low-normal BMI (≥5th to <25th percentile), high-normal BMI (≥75th to <85th percentile) and overweight (85th to 95th percentile) also were associated with a higher risk for cancer(high-normal BMI: HR, 1.49; 95% CI, 1.05-2.13; overweight: HR, 1.97; 95% CI, 1.39-2.80). The estimated population-attributable fraction because of overweight and obesity was 10.9% (95% CI, 6.1%-15.6%).

CONCLUSIONS

Men and women who were obese or overweight as adolescents are at an increased risk for subsequent pancreatic cancer.