The relationship of life-course patterns of adiposity with type 2 diabetes, depression, and their comorbidity in the Northern Finland Birth Cohort 1966

OBJECTIVES

Type 2 diabetes (T2D) and comorbid depression challenges clinical management particularly in individuals with overweight. We aim to explore the shared etiology, via lifecourse adiposity, between T2D and depression.

METHODS

We used data from birth until 46years from Northern Finland Birth Cohort 1966 (n = 6,372; 53.8% females). We conducted multivariate analyses on three outcomes: T2D (4.2%), depression (19.2%) and as comorbidity (1.8%). We conducted (i) Path analysis to clarify time-dependent body mass index (BMI) related pathways, including BMI polygenic risk scores (PRS); and (ii) Cox regression models to assess whether reduction of overweight between 7years and 31years influence T2D, depression and/or comorbidity. The models were tested for covariation with sex, education, smoking, physical activity, and diet score.

RESULTS

The odd ratios (OR) of T2D in individuals with depression was 1.68 [95% confidence interval (CI): 1.34-2.11], and no change in estimate was observed when adjusted for covariates. T2D and comorbidity showed similar patterns of relationships in the path analyses (P < 0.001). The genetic risk for obesity (PRS BMI) did not show direct effect on T2D or comorbidity in adulthood but indirectly through measures of adiposity in early childhood and mid-adulthood in the path analysis (P < 0.001). Having early-onset of overweight at 7years and 31years showed highest risk of T2D (OR 3.8, 95%CI 2.4-6.1) and comorbidity (OR 5.0, 95%CI 2.7-9.5), with mild-to-moderate attenuation with adjustments. Depression showed no significant associations.

CONCLUSIONS

We found evidence for overweight since childhood as a risk factor for T2D and co-morbidity between T2D and depression, influenced moderately by lifestyle factors in later life. However, no shared early life adiposity related risk factors were observed between T2D and depression when assessed independently in this Finnish setting.

Early Childhood Growth and Risk of Adult Cerebrovascular Disease: The NFBC1966

BACKGROUND

Low birth weight is associated with an increased risk of adulthood cerebrovascular disease (CVD). Not much is known about effects of early childhood growth. We studied whether the risk of adult CVD is associated with growth or nutritional factors during early childhood.

METHODS

Within the Northern Finland Birth Cohort 1966, 11 991 persons were followed from birth to 52 years of age. CVD diagnoses were extracted from national hospital and death registers with diagnostic coding based on the World Health Organization recommendations. Cox proportional hazard models were used to estimate associations of childhood growth variables, growth trajectories (by Latent Class Growth Modeling), and nutritional factors with adult CVD, for example, ischemic and hemorrhagic strokes. The analyses were adjusted for childhood socioeconomic status and birth weight.

RESULTS

A total of 453 (3.8%) CVDs were recorded during follow-up. Among females, groups with low early childhood weight and height had an increased risk for adulthood ischemic CVDs, with an adjusted hazard ratio of 1.97 (95% CI, 1.21-3.20) and 2.05 (CI, 1.11-3.81), respectively. In addition, females with body mass index over 1 SD at body mass index rebound had an increased risk for ischemic CVDs (adjusted hazard ratio, 1.90 [CI, 1.19-3.04]) compared with females with body mass index -1 to +1 SD. These associations were not found among males.

CONCLUSIONS

The findings suggest that timing of weight gain during childhood is of significance for development of CVD risk among females.

LongITools: Dynamic longitudinal exposome trajectories in cardiovascular and metabolic noncommunicable diseases

The current epidemics of cardiovascular and metabolic noncommunicable diseases have emerged alongside dramatic modifications in lifestyle and living environments. These correspond to changes in our "modern" postwar societies globally characterized by rural-to-urban migration, modernization of agricultural practices, and transportation, climate change, and aging. Evidence suggests that these changes are related to each other, although the social and biological mechanisms as well as their interactions have yet to be uncovered. LongITools, as one of the 9 projects included in the European Human Exposome Network, will tackle this environmental health equation linking multidimensional environmental exposures to the occurrence of cardiovascular and metabolic noncommunicable diseases.

BMI in childhood and adolescence is associated with impaired reproductive function-a population-based cohort study from birth to age 50 years

STUDY QUESTION

What is the association between childhood and adolescent BMI and reproductive capacity in women?

SUMMARY ANSWER

Adolescent girls with obesity had an increased risk of infertility and childlessness in adulthood independently of their marital status or the presence of polycystic ovary syndrome (PCOS).

WHAT IS KNOWN ALREADY

Girls with obesity (BMI (kg/m2)>95th percentile) more often exhibit menstrual irregularities and infertility problems as compared to those with normal weight, and premenarcheal girls with obesity have an increased risk of childlessness and infertility in adulthood. Follow-up studies on the relation between childhood and adolescence growth patterns and fertility or parity throughout the reproductive life span are limited.

STUDY DESIGN, SIZE, DURATION

A prospective, population-based cohort study (the Northern Finland birth cohort 1966) was performed with 5889 women born in 1966 and followed from birth to age 50 years. Postal questionnaires at ages 31 and 46 years addressed questions on reproductive capacity evaluated by decreased fecundability, need for infertility assessment and treatment by 46 years of age. Childlessness and number of children by age 50 years were recovered from registers. Women who did not report ever having attempted to achieve pregnancy (n = 1507) were excluded. The final study population included 4382 women who attempted to achieve pregnancy before age 46 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on BMI were collected by trained personnel at all stages. We assessed association with both prospectively measured BMI at various time points and with early adiposity phenotypes derived from linear mixed models including the timing and the BMI at adiposity peak (AP) and adiposity rebound (AR). Self-reported infertility assessments and treatments were assessed at ages 31 and 46 years. Data on deliveries were collected from the national birth register. Decreased fecundability was defined at age 31 years as time to achieve pregnancy over 12 months. Logistic regression analyses were conducted with adjustments for marital status, education level and smoking at age 31 years. Women with PCOS were excluded from stratification-based sensitivity analyses. Obesity at a specific age group was defined by having at least one BMI value above the 95th percentile during the related period.

MAIN RESULTS AND THE ROLE OF CHANCE

BMI at the age of AR (5-7 years) was not associated with fertility outcomes after adjustments, but girls with AR <5.1 years had a higher risk of remaining childless compared to girls with AR over 5.1 years (adjusted odds ratio (OR): 1.45 (1.10-1.92)). At ages 7-10 and 11-15 years, obesity was associated with decreased fecundability (adjusted OR 2.05 (1.26-3.35) and 2.04 (1.21-3.44), respectively) and a lower number of children. At age 11-15 years, both overweight and obesity were associated with a higher risk of childlessness (adjusted OR 1.56 (1.06-2.27), 1.77 (1.02-3.07), respectively), even after excluding women with PCOS. Underweight at age 11-15 years was associated with an increased risk for infertility treatment (adjusted OR 1.55 (1.02-2.36)) and a tendency for an increased risk for infertility assessment (adjusted OR 1.43 (0.97-2.10)) after excluding women with PCOS.

LIMITATIONS, REASON FOR CAUTION

Despite a high participation rate throughout the follow-up, some growth data for children over the different age groups were missing. Infertility outcomes were self-reported. A potential over-diagnosis of obesity may have reduced the significance of the association between childhood obesity and fertility outcomes, and the diagnosis of PCOS was self-reported.

WIDER IMPLICATIONS OF THE FINDINGS

This study supports previous results showing that girls with obesity in late childhood and in adolescence displayed reduced fertility and an increased risk of remaining childless in adulthood, independently of marital history and PCOS in adulthood. These findings corroborate the body of evidence for a causal relation between early adiposity and the reproductive functions in women. We recommend reinforcing the prevention of obesity in school-age girls to reduce the risk of impaired reproductive functions.

STUDY FUNDING/COMPETING INTEREST(S)

NFBC1966 received financial support from University of Oulu Grant no. 65354, Oulu University Hospital Grant no. 2/97, 8/97, Ministry of Health and Social Affairs Grant no. 23/251/97, 160/97, 190/97, National Institute for Health and Welfare, Helsinki Grant no. 54121, Regional Institute of Occupational Health, Oulu, Finland Grant no. 50621, 54231. The Finnish Medical Foundation, the North Ostrobothnia Regional Fund, the Academy of Finland (project grants 315921, 104781, 120315, 129269, 1114194, 24300796), Center of Excellence in Complex Disease Genetics and SALVE, the Sigrid Juselius Foundation, Biocenter Oulu, University Hospital Oulu and University of Oulu (75617), Jalmari ja Rauha Ahokkaan säätiö, The Finnish Medical Foundation, Medical Research Center Oulu, National Institute for Health Research (UK). M. R. J., S. S. and R. N. received funding by the Academy of Finland (#268336) and the European Union's Horizon 2020 research and innovation program (under Grant agreement no. 633595 for the DynaHEALTH action and GA 733206 for LifeCycle). The funders had no role in study design, in the collection, analysis and interpretation of the data, in the writing of the article and in the decision to submit it for publication. The authors have no conflict of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Body size during adulthood, but not in childhood, associates with endometriosis, specifically in the peritoneal subtype-population-based life-course data from birth to late fertile age

INTRODUCTION

Endometriosis is a common gynecological condition causing chronic pain and infertility. Only limited data exist on body size during childhood and adolescence in affected women. A leaner body shape has been associated with endometriosis in adults. However, longitudinal follow-up data from birth to adulthood are lacking. The aim of this study was to assess the association between body size and endometriosis from birth to age 46 years. We also performed in-depth analysis of the endometriosis subtypes.

MATERIAL AND METHODS

This was a population-based study including 96% of the children born in Northern Finland in 1966. Endometriosis case identification was based on (a) the World Health Organization's International Statistical Classification of Diseases code documentation from national hospital discharge registers and (b) self-reported diagnosis. A total of 348 women with endometriosis (203 in subtype analysis) and 3487 women without endometriosis were identified. Pregnancy, birth, and growth data up to adolescence were collected from welfare clinical records. Follow-up data of the Northern Finland Birth Cohort 1966 were collected at ages 14, 31, and 46 years through postal questionnaires and clinical examinations and included height, weight, and waist and hip circumference measurements. The associations between endometriosis and body size were assessed using logistic regression models.

RESULTS

Body sizes in childhood and adolescence were comparable between women developing endometriosis and those not developing endometriosis. On average, the risk for endometriosis was 2% lower for every kilogram of weight (odds ratio [OR] 0.98, 95% CI 0.97-1.00) and 6% lower for every body mass index unit (OR 0.94, 95% CI 0.90-0.99) at age 31. By age 46, a lower risk for peritoneal endometriosis was observed with greater weight (OR 0.95, 95% CI 0.92-0.98), weight gain from age 14 to age 46 years (OR 0.97, 95% CI 0.93-1.00), body mass index (OR 0.90, 95% CI 0.82-0.98), waist circumference (OR 0.95, 95% CI 0.92-0.99), and waist-hip ratio (OR 0.41, 95% CI 0.21-0.78).

CONCLUSIONS

This study provides further evidence of the associations between endometriosis and body size and adiposity, specifically in women with peritoneal endometriosis. The associations are evident in adulthood but not in childhood or adolescence.

Possible Modifiers of the Association Between Change in Weight Status From Child Through Adult Ages and Later Risk of Type 2 Diabetes

OBJECTIVE

We investigated the association between changes in weight status from childhood through adulthood and subsequent type 2 diabetes risks and whether educational attainment, smoking, and leisure time physical activity (LTPA) modify this association.

RESEARCH DESIGN AND METHODS

Using data from 10 Danish and Finnish cohorts including 25,283 individuals, childhood BMI at 7 and 12 years was categorized as normal or high using age- and sex-specific cutoffs (<85th or ≥85th percentile). Adult BMI (20-71 years) was categorized as nonobese or obese (<30.0 or ≥30.0 kg/m², respectively). Associations between BMI patterns and type 2 diabetes (989 women and 1,370 men) were analyzed using Cox proportional hazards regressions and meta-analysis techniques.

RESULTS

Compared with individuals with a normal BMI at 7 years and without adult obesity, those with a high BMI at 7 years and adult obesity had higher type 2 diabetes risks (hazard ratio [HR]_girls 5.04 [95% CI 3.92-6.48]; HR_boys 3.78 [95% CI 2.68-5.33]). Individuals with a high BMI at 7 years but without adult obesity did not have a higher risk (HR_girls 0.74 [95% CI 0.52-1.06]; HR_boys 0.93 [95% CI 0.65-1.33]). Education, smoking, and LTPA were associated with diabetes risks but did not modify or confound the associations with BMI changes. Results for 12 years of age were similar.

CONCLUSIONS

A high BMI in childhood was associated with higher type 2 diabetes risks only if individuals also had obesity in adulthood. These associations were not influenced by educational and lifestyle factors, indicating that BMI is similarly related to the risk across all levels of these factors.

Early determinants of metabolically healthy obesity in young adults: study of the Northern Finland Birth Cohort 1966

BACKGROUND

A body of literature suggests a metabolically healthy phenotype in individuals with obesity. Despite important clinical implications, the early origins of metabolically healthy obesity (MHO) have received little attention.

OBJECTIVE

To assess the prevalence of MHO among the Northern Finland Birth Cohort 1966 (NFBC1966) at 31 years of age, examine its determinants in early life taking into account the sex specificity.

METHODS

We studied 3205 term-born cohort participants with data available for cardio-metabolic health outcomes at 31 years, and longitudinal height and weight data. After stratifying the population by sex, adult BMI and a strict definition of metabolic health (i.e., no risk factors meaning metabolic health), we obtained six groups. Repeated childhood height and weight measures were used to model early growth and early adiposity phenotypes. We employed marginal means adjusted for mother and child covariates including socio-economic status, birth weight and gestational-age, to compare differences between the groups.

RESULTS

The prevalence of adult MHO was 6% in men and 13.5% in women. Differences in adult metabolic status were linked to alterations in BMI and age at adiposity peak in infancy (p < 0.0003 in men and p = 0.027 in women), and BMI and age at adiposity rebound (AR) (p < 0.0001 irrespective of sex). Compared to MHO, metabolically unhealthy obese (MUO) women were five and a half months younger at AR (p = 0.007) with a higher BMI while MUO men were four months older (p = 0.036) with no difference in BMI at AR.

CONCLUSION

At the time of AR, MHO women appeared to be older than their MUO counterparts while MHO men were younger. These original results support potential risk factors at the time of adiposity rebound linked to metabolic health in adulthood. These variations by sex warrant independent replication.

Accumulated exposure to unemployment is related to impaired glucose metabolism in middle-aged men: A follow-up of the Northern Finland Birth Cohort 1966

AIMS

We explored whether registered unemployment is associated with impaired glucose metabolism in general population.

METHODS

Based on Northern Finland Birth Cohort 1966 at 46 years, we analyzed the oral glucose tolerance tests of 1970 men and 2544 women in relation to their preceding three-year employment records in three categories of unemployment exposure: no (employed), low (≤1-year) and high exposure (>1-year).

RESULTS

Among men, pre-diabetes was found in 19.2% of those with no unemployment, 23.0% with low and 27.0% with high exposure, the corresponding figures for screen-detected type 2 diabetes were 3.8%, 3.8% and 9.2% (p<0.01). Among women, analogous figures for pre-diabetes were 10.0%, 12.6% and 16.2% and for screen-detected type 2 diabetes 1.7%, 3.4% and 3.6% (p<0.01). Men with high exposure to unemployment had a higher risk for pre-diabetes (OR 1.61, CI 95% 1.03-2.51) and screen-detected type 2 diabetes (OR 2.58 95% CI 1.23-5.44) than employed men, after adjustment for education, smoking, alcohol intake, physical activity and body mass index. Among women, associations were attenuated in the adjusted models.

CONCLUSIONS

High exposure to unemployment may predispose to type 2 diabetes in middle-aged men. For clinicians, awareness of the patient's unemployment status may be helpful in recognizing undiagnosed cases.