Comparisons of the strength of associations with future type 2 diabetes risk among anthropometric obesity indicators, including waist-to-height ratio: a meta-analysis

Comparison of traditional diabetes risk scores and HbA1c to predict type 2 diabetes mellitus in a population based cohort study

AIMS

Compare performances of diabetes risk scores and glycated hemoglobin (HbA1c) to estimate the risk of incident type 2 diabetes mellitus (T2DM) in Northeast Germany.

METHODS

We studied 2916 subjects (20 to 81years) from the Study of Health in Pomerania (SHIP) in a 5-year follow-up period. Diabetes risk scores included the Cooperative Health Research in the Region of Augsburg (KORA) base model, the Danish diabetes risk score and the Data from the Epidemiological Study on the Insulin Resistance syndrome (D.E.S.I.R) clinical risk score. We assessed the performance of each of the diabetes risk scores and the HbA1c for 5-year risk of T2DM by the area under the receiver-operating characteristic curve (AUC) and calibration plots.

RESULTS

In SHIP, the incidence of T2DM was 5.4% (n=157) in the 5-year follow-up period. Diabetes risk scores and HbA1c achieved AUCs ranging from 0.76 for the D.E.S.I.R. clinical risk score to 0.82 for the KORA base model. For diabetes risk scores, the discriminative ability was lower for the age group 55 to 74years. For HbA1c, the discriminative ability also decreased for the group 55 to 74years while it was stable in the age group 30 to 64years old.

CONCLUSIONS

All diabetes risk scores and the HbA1c showed a good prediction for the risk of T2DM in SHIP. Which model or biomarker should be used is driven by its context of use, e.g. the practicability, implementation of interventions and availability of measurement.

Adiposity, breast density, and breast cancer risk: epidemiological and biological considerations

Excess total body fat and abdominal adipose tissue are recognized risk factors for metabolic diseases but also for some types of cancers, including breast cancer. Several biological mechanisms in connection with local and systemic effects of adiposity are believed to be implicated in breast cancer development, and may involve breast fat. Breast adipose tissue can be studied through mammography by looking at breast density features such as the nondense area mainly composed of fat, or the percent breast density, which is the proportion of fibroglandular tissue in relation to fat. The relation between adiposity, breast density features, and breast cancer is complex. Studies suggest a paradoxical association as adiposity and absolute nondense area correlate positively with each other, but in contrast to adiposity, absolute nondense area seems to be associated negatively with breast cancer risk. As breast density is one of the strongest risk factors for breast cancer, it is therefore critical to understand how these factors interrelate. In this review, we discuss these relations by first presenting how adiposity measurements and breast density features are linked to breast cancer risk. Then, we used a systematic approach to capture the literature to review the relation between adiposity and breast density features. Finally, the role of adipose tissue in carcinogenesis is discussed briefly from a biological perspective.

Comparison of relationships between four common anthropometric measures and incident diabetes

AIMS

First, to conduct a detailed exploration of the prospective relations between four commonly used anthropometric measures with incident diabetes and to examine their consistency across different population subgroups. Second, to compare the ability of each of the measures to predict five-year risk of diabetes.

METHODS

We conducted a meta-analysis of individual participant data on body mass index (BMI), waist circumference (WC), waist-hip and waist-height ratio (WHtR) from the Obesity, Diabetes and Cardiovascular Disease Collaboration. Cox proportional hazard models were used to estimate the association between a one standard deviation increment in each anthropometric measure and incident diabetes. Harrell's concordance statistic was used to test the predictive accuracy of each measure for diabetes risk at five years.

RESULTS

Twenty-one studies with 154,998 participants and 9342 cases of incident diabetes were available. Each of the measures had a positive association with incident diabetes. A one standard deviation increment in each of the measures was associated with 64-80% higher diabetes risk. WC and WHtR more strongly associated with risk than BMI (ratio of hazard ratios: 0.95 [0.92,0.99] - 0.97 [0.95,0.98]) but there was no appreciable difference between the four measures in the predictive accuracy for diabetes at five years.

CONCLUSIONS

Despite suggestions that abdominal measures of obesity have stronger associations with incident diabetes and better predictive accuracy than BMI, we found no overall advantage in any one measure at discriminating the risk of developing diabetes. Any of these measures would suffice to assist in primary diabetes prevention efforts.

Adiposity and incident diabetes within 4 years of follow-up: the Guangzhou Biobank Cohort Study

AIM

Whether different adiposity measures predict incident diabetes differentially in general Chinese populations is unclear. We investigated this in Chinese people aged 50+ years in the Guangzhou Biobank Cohort Study.

METHODS

Waist circumference and BMI were measured at baseline, and fasting glucose was measured at both baseline and follow-up examinations. Incident diabetes was defined as fasting glucose ≥ 7.0 mmol/l, glucose after 2-h oral glucose tolerance test ≥ 11.1 mmol/l, and/or self-reported physician-diagnosed diabetes during the follow-up period.

RESULTS

Of 15 752 people without diabetes at baseline from 2003 to 2008, 1779 (11.3%) developed incident diabetes during the follow-up from 2008 to 2012 (mean = 3.6 years, sd = 1.0). After mutually adjusting each other and adjusting for other potential confounders, waist circumference showed a higher predictive value than BMI. The odds ratio (OR) (95% confidence interval (CI) was 1.50 (95% CI 1.37-1.64) for a 1 sd increment in waist circumference and 1.21 (95% CI 1.11-1.33), for a 1 sd increment in BMI. Similarly, after mutual adjustment, abdominal obesity was associated with an almost twofold odds of incident diabetes (OR 1.93, 95% CI 1.71-2.17), which was higher than that for general obesity (OR 1.76, 95% CI 1.50-2.06). The area under receiver operating characteristic curve (AUC) for waist circumference was higher than that for BMI [AUC = 0.676 (95% CI 0.660-0.686) vs. 0.665 (95% CI 0.651-0.678), P = 0.02].

CONCLUSION

Abdominal obesity predicted incident diabetes in older people better than general obesity. Our findings may be an early warning signal for local government or public health practitioners to develop and investigate more effective intervention programmes for diabetes, and should also be disseminated to the public to pay more attention to this important public health issue.

Effect of synergistic interaction between abnormal adiposity-related metabolism and prediabetes on microalbuminuria in the general population

Central obesity and related metabolic components are important risks for microalbuminuria. To describe the effects of interactions between central obesity and related metabolic components on microalbuminuria, we conducted a nation-wide, population-based interaction analysis using cardio-metabolic index (CMI) as a candidate indicator of central obesity and related abnormal lipid metabolism. We recruited native Koreans aged 20 years or older with no medical illness. A total of 5398 participants were divided into quintiles according to CMI with sex as a covariate factor. Participants in the highest CMI quintile had elevated blood pressure (BP), increased glycemic exposure, poor lipid profile, and increased urine albumin-to-creatinine ratio compared to other lower quintiles. Multiple logistic regression models adjusted for age, sex, systolic BP, and diastolic BP showed that CMI had an independent association with increased glycemic exposure and increased urine albumin-to-creatinine ratio. Our interaction analysis revealed a significant interaction between the highest CMI quintile and prediabetes with an increased risk of microalbuminuria (adjusted RERI = 0.473, 95% CI = 0.464–0.482; adjusted AP = 0.276, 95% CI = 0.156–0.395; adjusted SI = 2.952, 95% CI = 1.234–4.670). Our findings suggest a significant association between central obesity-related abnormal lipid metabolism and prediabetes, and their interaction may exert a synergistic effect on renal vascular endothelial dysfunction even before the appearance of full-blown diabetes mellitus. To confirm these findings, large population-based prospective studies are needed.

Comparison of body mass index at diagnosis of diabetes in a multi-ethnic population: A case-control study with matched non-diabetic controls

AIMS

To investigate the probability of developing type 2 diabetes mellitus (T2DM) at different body mass index levels compared to matched non-diabetic controls in a multi-ethnic population.

MATERIALS AND METHODS

This was a case-control study of 90 367 patients with incident diabetes and 362 548 age-sex-ethnicity matched controls from UK primary care. The probability of developing T2DM was estimated.

RESULTS

Case and control patients were 56 years old at index and 56% were male. Patients with T2DM had significantly higher mean BMI levels by about 5 kg/m² at diagnosis (32.2 kg/m² ) compared to the matched controls (27.4 kg/m² ). White Europeans (n = 79 270), African-Caribbeans (n = 4115) and South Asians (n = 7252) were 58, 48 and 46 years old with a mean BMI of 32.5, 31.1 and 29.2 kg/m² , respectively, at diagnosis. More South Asians developed T2DM at BMI below 30 kg/m² (38%) than White Europeans (26%) and African-Caribbeans (29%) (all P  < .01). Within the 18 to 70-year age range, South Asian males and females had a significantly higher probability of developing diabetes in the continuously measured BMI range of 18 to 30 kg/m² , compared to White Europeans and African-Caribbeans. Across all age groups <70 years, South Asians and African-Caribbeans had a significantly higher probability of developing T2DM in the normal weight and overweight categories, compared to White Europeans. However, this risk pattern of developing diabetes was reversed amongst the obese in all age groups.

CONCLUSION

Risk patterns of developing diabetes at different levels of obesity varies among ethnic groups across all ages, while South Asians and African-Caribbeans carry the highest risk at a younger age and at lower adiposity burden.

Increases in waist circumference independent of weight in Mongolia over the last decade: the Mongolian STEPS surveys

Background

In Mongolia, mean waist circumference (WC) has increased dramatically over the last decade, however, it is unknown whether these increases have been greater than corresponding increases in weight. In this study we aimed to assess whether recent increases in WC were greater than expected from changes in weight in Mongolian adults.

Methods

We used data on 13260 Mongolian adults, aged between 18 and 64 years, who participated in one of three (2005, 2009, 2013) nationally representative cross-sectional surveys. Linear regression was used to estimate changes in mean WC over time, adjusted for age, sex, height and weight. We also estimated the age-standardised prevalence for four obesity classification categories (not obese; obese by WC only; obese by body mass index (BMI) only; obese by both BMI and WC) at each survey year.

Results

The estimated mean WC in 2009 and 2013, respectively, was 1.26 cm (95% CI: 0.35 to 2.17) and 1.88 cm (95% CI: 1.09 to 2.67) greater compared to 2005, after adjusting for age, sex, height and weight. Between 2005 and 2013, the age-standardised prevalence of those obese according to both BMI and WC increased from 8.0 to 13.6% for men and from 16.5 to 25.5% for women. During the same period, the percentage who were obese by WC only increased from 1.8 to 4.8% for men and from 16.5 to 26.8% for women. In contrast, the percentage who were obese by BMI only remained relatively stable (women: 2.4% in 2005 to 1.0% in 2013; men: 2.7% in 2005 to 4.0% in 2013).

Conclusion

Over the last decade, among Mongolian adults, there has been substantially greater increase in WC and the prevalence of abdominal obesity than would be expected from increases in weight. Women are at greater risk than men of being misclassified as not obese if obesity is defined using BMI only. Obesity should be monitored using WC in addition to BMI to ensure the prevalence of obesity is not underestimated.

Is waist circumference ≥102/88cm better than body mass index ≥30 to predict hypertension and diabetes development regardless of gender, age group, and race/ethnicity? Meta-analysis

Between body mass index (BMI) ≥30 and waist circumference (WC) ≥102/88cm, we investigated which of the two measures is a better predictor of two of the most common chronic diseases - diabetes mellitus and hypertension while also examining differential association by gender, age group, and race/ethnicity. Meta-analysis was conducted for all longitudinal studies with at least 12months of follow-up published up to April 2015. Ratio of relative risk (rRR) and relative risk of diseases were computed and compared by baseline obesity measurement. The final sample included 23 longitudinal observation studies involving 62 study arms with 259,200 individuals. WC≥102/88cm was a better predictor than BMI≥30 for development of diabetes (rRR=0.81, 95% CI=0.68-0.96), but not for hypertension (rRR=0.92, 95% CI=0.80-1.06). Subgroup analyses showed WC≥102/88cm was a better predictor for diabetes in women than men, and for ages 60 and older than other ages. Only WC≥102/88cm, not BMI≥30, predicted development of hypertension among Hispanic/Latinos. Neither BMI≥30 nor WC≥102/88cm were significant predictors of hypertension when age group was controlled. Central obesity may be a more serious risk factor for diabetes development in women and for older ages. The predictive power of BMI≥30 or WC≥102/88cm in hypertension development should not be emphasized as either could mask the effect of age.

Association between body mass index and diabetes mellitus in tuberculosis patients in China: a community based cross-sectional study

BACKGROUND

We planned to determine the association of body mass index (BMI) with diabetes mellitus (DM) and impaired fasting glucose (IFG) in Chinese pulmonary tuberculosis (PTB) patients.

METHODS

3,505 newly-diagnosed PTB patients registered in PTB clinics in Linyi of China between September 2010 and March 2013 were enrolled. DM and IFG were identified based on fasting plasma glucose levels. ROC analysis was used to predict the ability of screening of BMI for DM and IFG in PTB patients.

RESULTS

Compared with 18.5-23.9 kg/m², patients with DM and IFG had significantly increased trends when BMI ≥ 24.0 kg/m², and aORs were 2.28 (95%CI 1.44-3.60) and 1.30 (95%CI 1.04-1.64), respectively. After adjustment for age, gender, and educational level, there was an increased odd in BMI ≥ 23.41 kg/m² for IFG, and a decreased odd in BMI < 19.82 kg/m² for DM (p < 0.05). The cut-offs of BMI for screening IFG and DM in PTB patients were 22.22 kg/m² (AUC 0.56) and 22.34 kg/m² (AUC 0.59).

CONCLUSIONS

In PTB patients, BMI is significantly associated with IFG and DM. However, the predictive power of BMI was not sufficient, so it may only be a limited screening tool for DM and IFG among PTB patients in China.

The association between body mass index and mortality among Asian peritoneal dialysis patients: A meta-analysis

BACKGROUND

Previous studies have revealed that increased body mass index (BMI) is associated with decreased mortality among hemodialysis patients. However, few studies have dealt with the association between BMI and mortality among patients undergoing peritoneal dialysis (PD) and even fewer studies have focused on the Asian PD patients. The reported studies were often non-conclusive and some even yielded contradictory results. This paper, to our best knowledge, registers the first attempt to systematically review the current literature and summarize new results on the association between BMI and mortality among the Asian PD population.

METHOD

A systematic literature review was performed in Medline and EMBASE to identify relevant cohort studies on all-cause and cardiovascular disease (CVD) mortality stratified by BMI categories tailored to Asians among the Asian PD population. We meta-analyzed individual results based on a random effect model, strictly complying with Preferred Reporting Items for Systematic Reviews and Meta-analysis.

RESULTS

The paper reviews seven cohort studies with a total of 3,610 Asian PD patients. Obese group (BMI = 25-29.9 kg/m2) was associated with higher risk of all-cause mortality (HR = 1.46, 95%CI [1.07-1.98]; p = 0.02) and CVD mortality (HR = 2.01, 95%CI [1.14-3.54]; p = 0.02), compared to the normal group (BMI = 18.5-22.9 kg/m2). The underweight group (BMI<18.5kg/m2) was also associated with an elevated risk of all-cause mortality (HR = 2.11, 95%CI [1.46-3.07]; p<0.001). No significant associations between BMI with all-cause mortality were found among the overweight group (23-24.9 kg/m2) (HR = 1.00, 95%CI [0.76-1.32]; p = 0.9). The association between BMI and CVD mortality risk among the underweight and overweight groups was found nonsignificant (p = 0.5 and 0.6 respectively).

CONCLUSION

Obesity is associated with increased mortality in Asian PD patients. The study indicates a "V-shaped" trend in the association between BMI and mortality in these patients.

Direct and Indirect Effects of Serum Uric Acid on Blood Sugar Levels in Patients with Prediabetes: A Mediation Analysis

PURPOSE

To estimate both direct and indirect effects (through obesity) of serum uric acid (SUA) on blood sugar in prediabetes patients.

METHODS

Prediabetes patients who came to the outpatient clinic of the Department of Family Medicine, Ramathibodi Hospital, were included in this cross-sectional study. Mediation analysis was applied to determine direct and indirect effects of SUA on glycemic parameters (fasting plasma glucose (FPG) and HbA1c) through waist circumference (WC). A mediation effect was estimated using the product-of-coefficient method with a bootstrap analysis of 1000 replications.

RESULTS

1043 patients were eligible for this study. Every 1 mg/dl increase in SUA was associated with an increase in WC and then was significantly associated with an increase in FPG by 0.082 mg/dl (95% CI: 0.010, 0.154). SUA was directly associated with FPG with a coefficient of 0.413 (95% CI: 0.049, 0.776). For HbA1c, every one mg/dl increase in SUA was associated with an increase in HbA1c level through WC by 0.006 (95% CI: 0.003, 0.010). However, SUA was not directly associated with HbA1c.

CONCLUSIONS

We found that an increase in SUA was directly and indirectly associated with increased FPG but the effect of SUA on HbA1c was shown when it was mediated through WC.

Utility of body mass index, waist circumference and waist-to-height ratio as screening tools for hyperglycemia in young people

OBJECTIVES

To evaluate the ability of BMI, WC and WHtR to discriminate hyperglycemia in young people, and to determine whether there is an increase in the accuracy with the addition of WC and/or WHtR to BMI.

SUBJECTS AND METHODS

A cross-sectional study was conducted on 1,139 schoolchildren aged 6 to 17 years from Northeastern Brazil. Body weight, height, WC and fasting glucose levels were measured, and the BMI and WHtR were calculated. The presence of hyperglycemia was defined as a fasting glucose level ≥ 100 mg/dL.

RESULTS

The prevalence of hyperglycemia was 6.6%. Strong correlations were observed between the anthropometric indicators studied (BMI vs. WC = 0.87; BMI vs. WHtR = 0.87; WC vs. WHtR = 0.90). Hyperglycemia was more likely to be present in young people with excess weight (PR = 1.70), high WC (PR = 1.85), and high WHtR (PR = 1.91). The accuracies to discriminate hyperglycemia were significant, but low, for the individual (BMI = 0.56; WC = 0.53; WHtR = 0.55) and combined indicators (BMI + WC = 0.55; BMI + WHtR = 0.55).

CONCLUSION

Our findings do not support the use of BMI, WC or WHtR as screening tools for hyperglycemia in children and adolescents.

Race/ethnic comparisons of waist-to-height ratio for cardiometabolic screening: The study of women's health across the nation

OBJECTIVE

To compare the performance of waist-to-height ratio as a screening tool for cardiometabolic conditions - hypertension, prediabetes/diabetes, dyslipidemia, and subclinical inflammation - in 5 race/ethnic groups of mid-life women.

METHODS

Waist-to-height ratio and 4 cardiometabolic conditions were assessed in 3033 premenopausal midlife women (249 Hispanic, 226 Chinese, 262 Japanese, 1435 European-American, and 861 African American). The areas under the receiver operating characteristic curve (AUROC) were compared across the five race/ethnic groups using waist-to-height ratio to determine the likelihood of the four cardiometabolic conditions.

RESULTS

The performance of waist-to-height ratio to detect one or more cardiometabolic conditions was comparable among all race/ethnic groups (AUROC > 0.60, p = 0.252), and was good/fair (AUROC > 0.60) when hypertension, prediabetes/diabetes, dyslipidemia, or subclinical inflammation were analyzed separately. The performance of waist-to-height ratio of 0.50 was skewed towards higher specificity among groups with low prevalence of cardiometabolic conditions and lower median waist-to-height ratio, and towards higher sensitivity among groups with high prevalence of cardiometabolic conditions and higher median waist-to-height ratio.

CONCLUSIONS

Waist-to-height ratio can be used for community-based screening of mid-life women who may need secondary prevention for cardiometabolic conditions. A simple public health message: "Keep your waist to less than half of your height" applies to midlife women.

Body mass index and the risk of all-cause mortality among patients with nonvalvular atrial fibrillation: a multicenter prospective observational study in China

BACKGROUND/OBJECTIVES

High body mass index (BMI) is associated with increased incident atrial fibrillation (AF) and mortality rate. In patients presenting with nonvalvular AF (NVAF), the prognostic relevance of BMI remains unclear.

SUBJECTS/METHODS

In this prospective observational study, a total of 1759 patients with NVAF (69.9±12.9 years old, 47.9% male) were divided into three clinical settings according to estimated stroke risks (CHADS₂ score ⩽1 (low), =2 (moderate) and ⩾3 (high)). The primary outcome was all-cause mortality, and the secondary outcomes included thromboembolism and major bleeding. Cox-proportional hazard models were used to estimate the association between BMI levels and clinical outcomes.

RESULTS

During a mean follow-up of 1 year representing 1974 patient-years at risk, 256 patients died, 142 suffered from thromboembolism and 17 developed major bleeding. Multivariate adjusted Cox analysis indicated that a BMI of 24.0-27.9 kg/m² was independently associated with improved survival among all patients (hazard ratio (HR) 0.689, 95% confidence interval (CI) 0.512-0.928; P=0.018) and patients at high stroke risk (HR 0.622, 95% CI 0.410-0.943; P=0.024), but not among those at low or moderate stroke risks. No associations were observed between BMI levels and the incidence of thromboembolic events in various clinical settings.

CONCLUSIONS

A paradoxical BMI-all-cause mortality risk association was observed in Chinese patients with NVAF, and this association was pronounced among patients at high stroke risk rather than in those at low stroke risk.

Comparison of body mass index, waist circumference, and waist to height ratio in the prediction of hypertension and diabetes mellitus: Filipino-American women cardiovascular study

The relative ability of three obesity indices to predict hypertension (HTN) and diabetes (DM) and the validity of using Asian-specific thresholds of these indices were examined in Filipino-American women (FAW). Filipino-American women (n = 382), 40–65 years of age were screened for hypertension (HTN) and diabetes (DM) in four major US cities. Body mass index (BMI), waist circumference (WC) and waist circumference to height ratio (WHtR) were measured. ROC analyses determined that the three obesity measurements were similar in predicting HTN and DM (AUC: 0.6–0.7). The universal WC threshold of ≥ 35 in. missed 13% of the hypertensive patients and 12% of the diabetic patients. The Asian WC threshold of ≥ 31.5 in. increased detection of HTN and DM but with a high rate of false positives. The traditional BMI ≥ 25 kg/m² threshold missed 35% of those with hypertension and 24% of those with diabetes. The Asian BMI threshold improved detection but resulted in a high rate of false positives. The suggested WHtR cut-off of ≥ 0.5 missed only 1% of those with HTN and 0% of those with DM. The three obesity measurements had similar but modest ability to predict HTN and DM in FAW. Using Asian-specific thresholds increased accuracy but with a high rate of false positives. Whether FAW, especially at older ages, should be encouraged to reach these lower thresholds needs further investigation because of the high false positive rates.

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WC, BMI and WHtR measurements cutoff points were higher in middle aged FAW.

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WC, BMI and WHtR measurements had similar ability to predict HTN and DM in FAW.

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Need to tailor thresholds of obesity measurements for specific Asian subgroups.

Polymorphisms FTO rs9939609, PPARG rs1801282 and ADIPOQ rs4632532 and rs182052 but not lifestyle are associated with obesity related-traits in Mexican children

Concerning the genetic factors of obesity, no consistent association between populations has been reported, which may be due to the frequency of polymorphisms, the lifestyle of studied populations and its interaction with other factors. We studied a possible association of polymorphisms FTO rs9939609, PPARG rs1801282, and ADIPOQ rs4632532 and rs182052 with obesity phenotypes in 215 Mexican children. Glucose, triglycerides, cholesterol, HDL and LDL were measured. In addition, weight, height, waist circumference and triceps skin thickness were recorded. High-energy diets and sedentary behavior were evaluated with a validated questionnaire. In contrast with other reports, only FTO rs9939609 was associated with obesity related-traits, including BMI (p = 0.03), waist circumference (p = 0.02), triceps skinfold (p = 0.03) and waist/height ratio (p = 0.01), and also with cholesterol levels (p = 0.02) and LDL (p = 0.009). Lower levels of triglycerides (p=0.04) were related with presence of PPARG rs1801282, while ADIPOQ rs4632532 showed an effect on HDL (p = 0.03) levels. On the other hand, diet, physical activity and screen time were not related with obesity. In summary, only FTO rs9939609 was associated with obesity related-traits, while PPARG2 rs1801282 and ADIPOQ rs4632532 were involved in lipid metabolism.

Vigorous Physical Work and Obesity?-the Paradox of the Californian Farmworker Population

A good understanding of underlying causes of obesity prevalence in the farmworker population is critical in finding effective strategies to fight obesity and related chronic diseases. There is growing evidence that the population of farmworkers fares poorly with regard to health status, but available data on obesity levels and related chronic diseases is scarce or missing. This study examined the prevalence of overweight and obesity among a sample of farmworker population in California. Results of the regression model indicate that along with demographic variables such as age and gender, several lifestyle and behavioral risk factors are associated with obesity of the farmworkers. Results from this study will inform the design of intervention efforts and policies to help improve the health status of the farmworker population at the community level and beyond.

Feasibility of body roundness index for identifying a clustering of cardiometabolic abnormalities compared to BMI, waist circumference and other anthropometric indices: the China Health and Nutrition Survey, 2008 to 2009

The body mass index (BMI) and waist circumference (WC) are commonly used anthropometric measures for predicting cardiovascular diseases risk factors, but it is uncertain which specific measure might be the most appropriate predictor of a cluster of cardiometabolic abnormalities (CMA) in Chinese adults. A body shape index (ABSI) and body roundness index (BRI) have been recently developed as alternative anthropometric indices that may better reflect health status. The main aims of this study were to investigate the predictive capacity of ABSI and BRI in identifying various CMA compared to BMI, WC, waist-to-hip ratio (WHpR), and waist-to-height ratio (WHtR), and to determine whether there exists a best single predictor of all CMA.We used data from the 2009 wave of the China Health and Nutrition Survey, and the final analysis included 8126 adults aged 18 to 85 years with available fasting blood samples and anthropometric measurements. Receiver-operating characteristic (ROC) analyses were conducted to assess the best anthropometric indices to predict the risk of hypertension, diabetes, dyslipidemia, hyperuricemia, and metabolic syndrome (MetS). Logistic regression models were fit to evaluate the OR of each CMA according to anthropometric indices.In women, the ROC analysis showed that BRI and WHtR had the best predictive capability in identifying all of CMA (area under the curves [AUCs] ranged from 0.658 to 0.721). In men, BRI and WHtR were better predictor of hypertension, diabetes, and at least 1 CMA (AUC: 0.668, 0.708, and 0.698, respectively), whereas BMI and WC were more sensitive predictor of dyslipidemia, hyperuricemia, and MetS. Furthermore, the ABSI showed the lowest AUCs for each CMA. According to the multivariate logistic regression analysis, BRI and WHtR were superior in discriminating hyperuricemia and at least 1 CMA while BMI performed better in predicting hypertension, diabetes, and MetS in women. In men, WC and BRI were the 2 best predictor of all CMA except MetS, and the ABSI was the worst.Our results showed the novel index BRI could be used as a single suitable anthropometric measure in simultaneously identifying a cluster of CMA compared to BMI and WHtR, especially in Chinese women, whereas the ABSI showed the weakest discriminative power.

A Fit-Fat Index for Predicting Incident Diabetes in Apparently Healthy Men: A Prospective Cohort Study

Background

The purpose of this study was to examine the impact of combined cardiorespiratory fitness and waist-to-height ratio in the form of a fit-fat index on incident diabetes risk. Additionally, the independent predictive performance of cardiorespiratory fitness, waist-to-height ratio, and body mass index also were estimated and compared.

Methods

This was a prospective cohort study of 10,381 men who had a normal electrocardiogram and no history of major chronic disease at baseline from 1979 to 2005. Random survival forest models and traditional Cox proportional hazards models were used to predict diabetes at 5-, 10-, and 15-year incidence horizons.

Results

Overall, 4.8% of the participants developed diabetes. Receiver operating characteristic curve analyses for incidence risk demonstrated good discrimination using random survival forest models across fitness and fatness measures; Cox models were poor to fair. The differences between fitness and fatness measures across horizons were clinically negligible. Smoothed random survival forest estimates demonstrated the impact of each fitness and fatness measure on incident diabetes was intuitive and graded.

Conclusions

Although fitness and fatness measures showed a similar discriminative ability in predicting incident diabetes, unique to the study was the ability of the fit-fat index to demonstrate a better indication of incident risk when compared to fitness or fatness alone. A single index combining cardiorespiratory fitness and waist-to-height ratio may be more useful because it can indicate improvements in either or both of the measures.

Visceral Fat Mass Has Stronger Associations with Diabetes and Prediabetes than Other Anthropometric Obesity Indicators among Korean Adults

PURPOSE

This study determined which obesity measurement correlates the best with diabetes and prediabetes.

MATERIALS AND METHODS

This cross-sectional study enrolled 1603 subjects (611 men, 992 women; age 30-64 years) at the Cardiovascular and Metabolic Diseases Etiology Research Center. Body mass index, waist circumference, waist-height ratio, waist-hip ratio, waist-thigh ratio, and visceral fat were used as measures of obesity. Visceral fat was acquired using dual-energy X-ray absorptiometry (DXA). The prevalences of diabetes and prediabetes were defined using the criteria in the American Diabetes Association 2015 guidelines.

RESULTS

After adjusting for age and other potential confounding factors, participants with a visceral fat mass in the upper 10th percentile had a higher odds ratio (OR) for diabetes and prediabetes than the upper 10th percentile of other adiposity indices [men, OR=15.9, 95% confidence interval (CI)=6.4-39.2; women, OR=6.9, 95% CI=3.5-13.7]. Visceral fat mass also had the highest area under the curve with diabetes and prediabetes in both men (0.69, 95% CI=0.64-0.73) and women (0.70, 95% CI=0.67-0.74) compared to other anthropometric measurements of obesity.

CONCLUSION

Visceral fat mass measured using DXA is an indicator of diabetes or prediabetes, due to its ability to differentiate between abdominal visceral and subcutaneous fat.

Inverse association between altitude and obesity: A prevalence study among andean and low-altitude adult individuals of Peru

OBJECTIVE

To determine the association between altitude and obesity in a nationally representative sample of the Peruvian adult population.

METHODS

This is a cross-sectional analysis of publicly available data from the Food and Nutrition National Center (CENAN, Peru), period 2009-2010. The Prevalence ratio of obesity and abdominal obesity was determined as a measure of association. Obesity and abdominal obesity were diagnosed based on direct anthropometric measurements.

RESULTS

The final data set consisted of 31,549 individuals ≥20 years old. The prevalence ratio of obesity was as follows: 1.00 between 0 and 499 m (reference category), 1.00 (95% confidence interval 0.87-1.16) between 500-1,499 m, 0.74 (0.63-0.86) between 1,500-2,999 m, and 0.54 (0.45-0.64) at ≥3,000 m, adjusting for age, sex, self-reported physical activity, out-migration rate, urbanization, poverty, education, and geographical latitude and longitude. In the same order, the adjusted prevalence ratio of abdominal obesity was 1.00, 1.01 (0.94-1.07), 0.93 (0.87-0.99), and 0.89 (0.82-0.95), respectively. We found an interaction between altitude and sex and between altitude and age (P < 0.001, for both interactions) on the association with obesity and abdominal obesity.

CONCLUSIONS

Among Peruvian adult individuals, we found an inverse association between altitude and obesity, adjusting for multiple covariates. This adjusted association varied by sex and age.

Association between alcohol consumption and the risk of incident type 2 diabetes: a systematic review and dose-response meta-analysis

BACKGROUND

Previous cohort studies have shown that moderate alcohol consumption was associated with a lower risk of type 2 diabetes (T2D). However, whether these associations differ according to the characteristics of patients with T2D remains controversial.

OBJECTIVE

The purpose of this study was to explore and summarize the evidence on the strength of the association between alcohol consumption and the subsequent risk of T2D by using a dose-response meta-analytic approach.

DESIGN

We identified potential studies by searching the PubMed, Embase, and Cochrane Library databases up to 24 March 2015. Prospective observational studies that evaluated the relation between alcohol consumption and the risk of T2D and reported its effect estimates with 95% CIs were included.

RESULTS

Analyses were based on 706,716 individuals (275,711 men and 431,005 women) from 26 studies with 31,621 T2D cases. We detected a nonlinear relation between alcohol consumption and the risk of T2D, which was identified in all cohorts (P-trend < 0.001, P-nonlinearity < 0.001), in men (P-trend < 0.001, P-nonlinearity < 0.001), and in women (P-trend < 0.001, P-nonlinearity < 0.001). Compared with the minimal category of alcohol consumption, light (RR: 0.83; 95% CI: 0.73, 0.95; P = 0.005) and moderate (RR: 0.74; 95% CI: 0.67, 0.82; P < 0.001) alcohol consumption was associated with a lower risk of T2D. However, heavy alcohol consumption had little or no effect on subsequent T2D risk. Furthermore, the summary RR ratio (RRR; male to female) of the comparison between moderate alcohol consumption and the minimal alcohol categories for T2D was significantly higher, and the pooled RRR (current smoker to never smoker) of light alcohol consumption was significantly reduced.

CONCLUSIONS

Light and moderate alcohol consumption was associated with a lower risk of T2D, whereas heavy alcohol consumption was not related to the risk of T2D.

Anthropometric markers and their association with incident type 2 diabetes mellitus: which marker is best for prediction? Pooled analysis of four German population-based cohort studies and comparison with a nationwide cohort study

OBJECTIVE

To compare the association between different anthropometric measurements and incident type 2 diabetes mellitus (T2DM) and to assess their predictive ability in different regions of Germany.

METHODS

Data of 10,258 participants from 4 prospective population-based cohorts were pooled to assess the association of body weight, body mass index (BMI), waist circumference (WC), waist-to-hip-ratio (WHR) and waist-to-height-ratio (WHtR) with incident T2DM by calculating HRs of the crude, adjusted and standardised markers, as well as providing receiver operator characteristic (ROC) curves. Differences between HRs and ROCs for the different anthropometric markers were calculated to compare their predictive ability. In addition, data of 3105 participants from the nationwide survey were analysed separately using the same methods to provide a nationally representative comparison.

RESULTS

Strong associations were found for each anthropometric marker and incidence of T2DM. Among the standardised anthropometric measures, we found the strongest effect on incident T2DM for WC and WHtR in the pooled sample (HR for 1 SD difference in WC 1.97, 95% CI 1.75 to 2.22, HR for WHtR 1.93, 95% CI 1.71 to 2.17 in women) and in female DEGS participants (HR for WC 2.24, 95% CI 1.91 to 2.63, HR for WHtR 2.10, 95% CI 1.81 to 2.44), whereas the strongest association in men was found for WHR among DEGS participants (HR 2.29, 95% CI 1.89 to 2.78). ROC analysis showed WHtR to be the strongest predictor for incident T2DM. Differences in HR and ROCs between the different markers confirmed WC and WHtR to be the best predictors of incident T2DM. Findings were consistent across study regions and age groups (<65 vs ≥ 65 years).

CONCLUSIONS

We found stronger associations between anthropometric markers that reflect abdominal obesity (ie, WC and WHtR) and incident T2DM than for BMI and weight. The use of these measurements in risk prediction should be encouraged.

High-risk glycated hemoglobin trajectories established by mid-20s: findings from a birth cohort study

OBJECTIVE

To describe the natural history of glycemia (as measured by glycated hemoglobin (HbA1c)) over 12 years using group-based trajectory modeling (GBTM), and to examine baseline predictors of trajectory.

RESEARCH DESIGN AND METHODS

HbA1c data collected at ages 26, 32 and 38 in the long-running, prospective Dunedin Multidisciplinary Health and Development Study were used to assign study members (n=893) to trajectories applying GBTM. A generalization of the model allowed the statistical linking of baseline demographic, smoking and anthropometric characteristics to group membership probability.

RESULTS

Mean HbA1c increased with age, as did prevalence of prediabetes, diabetes and dysglycemia. The greatest increase occurred between ages 26 and 32. Glycemic health status at age 26 predicted glycemic health status at age 38. 3 HbA1c trajectory groups were identified: 'low' (n=98, 11.0%); 'medium' (n=482, 54.0%); and 'high' (n=313, 35.0%) with mean HbA1c of 29.6, 34.1, and 38.7 mmol/mol, respectively, at age 38. High waist circumference (≥880 mm for women and ≥1020 mm for men), high waist-height ratio (≥0.50), and being a smoker at age 26 predicted membership of the least favorable trajectory over the next 12 years. High body mass index (≥30) at age 26 did not predict of trajectory.

CONCLUSIONS

Trajectories of HbA1c are established relatively early in adulthood. HbA1c levels, waist circumference, waist-height ratio, and smoking status at age 26 are valid clinical predictors for future dysglycemic risk. The identification of HbA1c trajectories and their predictors introduces the possibility of an individualized approach to prevention at an earlier stage than is currently done.

Combined association of fitness and central adiposity with health-related quality of life in healthy Men: a cross-sectional study

BACKGROUND

There is limited data examining the association of combined fitness and central obesity with health related quality of life (HRQoL) in adults. We examined the association of combined cardiorespiratory fitness (CRF) and waist-to-height ratio (WHtR) in the form of a fit-fat index (FFI) with the Physical Component Summary (PCS) and Mental Component Summary (MCS) HRQoL scores in United States Navy servicemen.

METHODS

As part of a health fitness assessment, a total of 709 healthy males aged 18-49 years completed a submaximal exercise test, WHtR measurement, and HRQoL survey (SF-12v2) between 2004 and 2006. FFI level was classified into thirds with the lowest FFI tertile serving as the referent group. PCS and MCS scores ≥50 were taken to indicate average or better. Logistic regression was used to obtain odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The prevalence of average or better HRQoL scores was lowest in the referent FFI tertile, PCS 60.2% and MCS 57.6%. Compared with the lowest FFI group in multivariate analyses, the OR (95% CI) of having average or better PCS was 1.63 (1.09-2.42) and 3.12 (1.95-4.99) for moderate and high FFI groups respectively; MCS was 1.70 (1.13-2.55) and 4.89 (3.03-7.89) for moderate and high FFI groups respectively (all P < 0.001). Consistent and progressive independent associations were observed between age and MCS, and also between CRF and MCS.

CONCLUSION

Among males in the United States Navy, higher levels of FFI were independently and more consistently associated with having average or better HRQoL (physical and mental) than other known predictors of HRQoL.

Are the Recent Secular Increases in Waist Circumference among Children and Adolescents Independent of Changes in BMI?

Background

Several studies have shown that the waist circumference of children and adolescents has increased over the last 25 years. However, given the strong correlation between waist circumference and BMI, it is uncertain if the secular trends in waist circumference are independent of those in BMI.

Methods

We analyzed data from 6- to 19-year-olds who participated in the 1988–1994 through 2011–2012 cycles of the National Health and Nutrition Examination Survey to assess whether the trends in waist circumference were independent of changes in BMI, race-ethnicity and age.

Results

Mean, unadjusted levels of waist circumference increased by 3.7 cm (boys) and 6.0 cm (girls) from 1988–94 through 2011–12, while mean BMI levels increased by 1.1 kg/m² (boys) and 1.6 kg/m² (girls). Overall, the proportional changes in mean levels of both waist circumference and BMI were fairly similar among boys (5.3%, waist vs. 5.6%, BMI) and girls (8.7%, waist vs. 7.7%, BMI). As assessed by the area under the curve, adjustment for BMI reduced the secular increases in waist circumference by about 75% (boys) and 50% (girls) beyond that attributable to age and race-ethnicity. There was also a race-ethnicity interaction (p < 0.001). Adjustment for BMI reduced the secular trend in waist circumference among non-Hispanic (NH) black children (boys and girls) to a greater extent (about 90%) than among other children.

Conclusions

Our results indicate that among children in the U.S., about 75% (boys) and 50% (girls) of the secular increases in waist circumference since 1988–94 can be accounted for by changes in BMI. The reasons for the larger independent effects among girls and among NH blacks are uncertain.

Prevalence of Diabetes and Associated Factors in the Uyghur and Han Population in Xinjiang, China

OBJECTIVE

To estimate the prevalence of diabetes and identify risk factors in the Uyghur and Han population in Xinjiang, China.

METHODS

A cross-sectional study in urban and rural areas in Xinjiang, including 2863 members of the Uyghur population and 3060 of the Han population aged 20 to 80 years, was conducted from June 2013 to August 2013. Data on fasting plasma glucose (FPG) and personal history of diabetes were used to estimate the prevalence of diabetes. Data on demographic characteristics, lifestyle risk factors, and lipid profiles were collected to identify risks factors using the multivariate logistic regression model.

RESULTS

In urban areas, the age- and gender-standardized prevalence of diabetes was 8.21%, and the age- and gender-standardized prevalence of diabetes was higher in the Uyghur population (10.47%) than in the Han population (7.36%). In rural areas, the age- and gender-standardized prevalence of diabetes was 6.08%, and it did not differ significantly between the Uyghur population (5.71%) and the Han population (6.59%). The results of the multivariate logistic regression analysis showed that older age, obesity, high triglycerides (TG), and hypertension were all associated with an increased risk of diabetes in the Uyghur and Han population. Urban residence and low high-density lipoprotein cholesterol (HDL-C) were associated with an increased risk of diabetes in the Uyghur population. Being an ex-drinker was associated with an increased risk of diabetes and heavy physical activity was associated with a decreased risk of diabetes in the Han population.

CONCLUSIONS

Our study indicates that diabetes is more prevalent in the Uyghur population compared with the Han population in urban areas. Strategies aimed at the prevention of diabetes require ethnic targeting.

Screening for Type 2 Diabetes and Dysglycemia in Saudi Arabia: Development and Validation of Risk Scores

OBJECTIVE

The prevalence of type 2 diabetes in Saudi Arabia is the highest worldwide after excluding small island nations. We developed and validated a noninvasive screening test based on demographic and clinical data for identifying adults with undiagnosed diabetes and dysglycemia in Saudi Arabia.

RESEARCH DESIGN AND METHODS

Data from 1,485 nonpregnant Saudi adults ≥20 years of age without a current diagnosis of diabetes were obtained from urban and rural primary healthcare centers in 2009. Clinical and demographic data were obtained through physician-administered interviews. Oral glucose tolerance test data were used to define diabetes (fasting plasma glucose ≥7.0 mmol/L or 2-h post-load glucose ≥11.1 mmol/L) and dysglycemia (fasting plasma glucose ≥5.6 mmol/L or 2-h post-load glucose ≥7.8 mmol/L). Predictive models were developed using data from 1,435 individuals. Multivariable logistic regression and receiver operating characteristic curves were used to develop and evaluate a separate risk score for both diabetes and dysglycemia. Scores were validated on a hold-out sample of 50 individuals.

RESULTS

The risk score for undiagnosed diabetes contained age, history of gestational diabetes, smoking, family history of diabetes, and central obesity with a sensitivity of 76.6% and a specificity of 52.1%. The dysglycemia risk score contained age, gestational diabetes, hypertension, and central obesity with a sensitivity of 71.2% and a specificity of 54.0%. All performed equally well, if not better, in the hold-out sample.

CONCLUSIONS

These risk scores can identify Saudi adults with undiagnosed diabetes or dysglycemia and should be validated in prospective studies.

Characterization of metabolically unhealthy normal-weight individuals: Risk factors and their associations with type 2 diabetes

OBJECTIVE

A proportion of type 2 diabetes cases arise from normal-weight individuals who can therefore be considered to be "metabolically unhealthy normal-weight" (MUH-NW). It remains unclear which factors account for this access risk. Our aims were to identify risk factors for type 2 diabetes in normal-weight individuals and to compare the strengths of their associations with type 2 diabetes to that observed in overweight and obese participants.

METHODS

A case-cohort, including 2027 sub-cohort participants and 706 incident type 2 cases, was designed within the population-based European Prospective Investigation into Cancer and Nutrition Potsdam study. Adjusted means and relative frequencies of anthropometric, lifestyle and biochemical risk factors were calculated in groups stratified by BMI and incident diabetes status. Cox regressions were applied to evaluate associations between these variables and diabetes risk stratified by BMI category.

RESULTS

MUH-NW individuals were characterized by known diabetes risk factors, e.g. they were significantly more likely to be male, former smokers, hypertensive, and less physically active compared to normal-weight individuals without incident diabetes. Higher waist circumference (women: 75.5 vs. 73.1cm; men: 88.0 vs. 85.1cm), higher HbA1c (6.1 vs. 5.3%), higher triglycerides (1.47 vs. 1.11 mmol/l), and higher levels of high sensitive C-reactive protein (0.81 vs. 0.51 mg/l) as well as lower levels of HDL-cholesterol (1.28 vs. 1.49 mmol/l) and adiponectin (6.32 vs. 8.25 μg/ml) characterized this phenotype. Stronger associations with diabetes among normal-weight participants compared to overweight and obese (p for interaction<0.05) were observed for height, waist circumference, former smoking, and hypertension.

CONCLUSIONS

Normal-weight individuals who develop diabetes have higher levels of diabetes risk factors, however, frequently still among the normal range. Still, hypertension, elevated HbA1c and lifestyle risk factors might be useful indicators of risk.

Prevalence and characteristics of non-obese diabetes in Japanese men and women: the Yuport Medical Checkup Center Study

BACKGROUND

This study examined the prevalence and characteristics of type 2 diabetes in non-obese subjects to compare their cardiometabolic markers to those without diabetes.

METHODS

Data were used from 17,098 men and 17,199 women from a voluntary health checkup program between 1998 and 2006 conducted in Japan. The prevalence of diabetes (fasting plasma glucose ≥ 7.0 mmol/L, hemoglobin A1c ≥ 6.5%, or known diabetes) was calculated in each subgroup of body mass index (group 1, <22; group 2, 22-25; group 3, 25-27.5; and group 4, ≥ 27.5). The effect of diabetes and obesity on risk of an abnormal level of cardiometabolic marker was evaluated with a logistic regression model.

RESULTS

In men, the prevalence of diabetes was 9.5% in total, 6.4%, 9.4%, 11.3% and 16.2% in group 1 through 4, respectively. In women, it accounted for 4.3% in total, 2.4%, 4.5%, 8.7% and 12.3% per group, respectively. Non-obese diabetic subjects (in group 1 and 2) accounted for 60.8% and 62.0% of all the diabetic subjects in men and women, respectively. Non-obese population accounted for 71.2% and 83.6% of all men and women, respectively. Levels of cardiometabolic markers were higher in diabetic subjects than in non-diabetic subjects in each subgroup. Diabetes was associated with each abnormal level of cardiometabolic marker independent of obesity.

CONCLUSION

Over 60% of the diabetic subjects in this Japanese population were not obese. Non-obese diabetes is not widely addressed and should be considered for increased public attention. The elevated levels of cardiometabolic markers may contribute to an increased risk of cardiovascular disease in non-obese diabetes.

Optimal central obesity measurement site for assessing cardiometabolic and type 2 diabetes risk in middle-aged adults

OBJECTIVES

Despite recommendations that central obesity assessment should be employed as a marker of cardiometabolic health, no consensus exists regarding measurement protocol. This study examined a range of anthropometric variables and their relationships with cardiometabolic features and type 2 diabetes in order to ascertain whether measurement site influences discriminatory accuracy. In particular, we compared waist circumference (WC) measured at two sites: (1) immediately below the lowest rib (WC rib) and (2) between the lowest rib and iliac crest (WC midway), which has been recommended by the World Health Organisation and International Diabetes Federation.

MATERIALS AND METHODS

This was a cross-sectional study involving a random sample of 2,002 men and women aged 46-73 years. Metabolic profiles and WC, hip circumference, pelvic width and body mass index (BMI) were determined. Correlation, logistic regression and area under the receiver operating characteristic curve analyses were used to evaluate obesity measurement relationships with metabolic risk phenotypes and type 2 diabetes.

RESULTS

WC rib measures displayed the strongest associations with non-optimal lipid and lipoprotein levels, high blood pressure, insulin resistance, impaired fasting glucose, a clustering of metabolic risk features and type 2 diabetes, in both genders. Rib-derived indices improved discrimination of type 2 diabetes by 3-7% compared to BMI and 2-6% compared to WC midway (in men) and 5-7% compared to BMI and 4-6% compared to WC midway (in women). A prediction model including BMI and central obesity displayed a significantly higher area under the curve for WC rib (0.78, P=0.003), Rib/height ratio (0.80, P<0.001), Rib/pelvis ratio (0.79, P<0.001), but not for WC midway (0.75, P=0.127), when compared to one with BMI alone (0.74).

CONCLUSIONS

WC rib is easier to assess and our data suggest that it is a better method for determining obesity-related cardiometabolic risk than WC midway. The clinical utility of rib-derived indices, or alternative WC measurements, deserves further investigation.

Relationship between Body Mass Index and Percent Body Fat in Vietnamese: Implications for the Diagnosis of Obesity

Background

The burden of obesity in Vietnam has not been well defined because there is a lack of reference data for percent body fat (PBF) in Asians. This study sought to define the relationship between PBF and body mass index (BMI) in the Vietnamese population.

Methods

The study was designed as a comparative cross-sectional investigation that involved 1217 individuals of Vietnamese background (862 women) aged 20 years and older (average age 47 yr) who were randomly selected from the general population in Ho Chi Minh City. Lean mass (LM) and fat mass (FM) were measured by DXA (Hologic QDR 4500). PBF was derived as FM over body weight.

Results

Based on BMI ≥30, the prevalence of obesity was 1.1% and 1.3% for men and women, respectively. The prevalence of overweight and obesity combined (BMI ≥25) was ~24% and ~19% in men and women, respectively. Based on the quadratic relationship between BMI and PBF, the approximate PBF corresponding to the BMI threshold of 30 (obese) was 30.5 in men and 41 in women. Using the criteria of PBF >30 in men and PBF >40 in women, approximately 15% of men and women were considered obese.

Conclusion

These data suggest that body mass index underestimates the prevalence of obesity. We suggest that a PBF >30 in men or PBF >40 in women is used as criteria for the diagnosis of obesity in Vietnamese adults. Using these criteria, 15% of Vietnamese adults in Ho Chi Minh City was considered obese.

Are the recent secular increases in the waist circumference of adults independent of changes in BMI?

BACKGROUND

Several studies showed that the waist circumference of US adults has increased over the past 25 y. However, because of the high correlation between waist circumference and body mass index (BMI; in kg/m²) (r ∼ 0.9), it is uncertain if these trends in waist circumference exceed those expected on the basis of BMI changes over this time period.

OBJECTIVE

We assessed whether the recent trend in waist circumference was independent of changes in BMI, age, and race-ethnicity.

DESIGN

We analyzed data from the 1999-2000 through 2011-2012 cycles of the NHANES.

RESULTS

The mean waist circumference increased by ∼2 cm (in men) and ∼4 cm (in women) in adults in the United States over this 12-y period. In men, this increase was very close to what would be expected because of the 0.7 increase in mean BMI over this period. However, in women, most of the secular increase in waist circumference appeared to be independent of changes in BMI (mean: 0.6), age, and race-ethnicity over the 12-y period. We estimated that, independent of changes in these covariates, the mean waist circumference increased by 0.2 cm in men and 2.4 cm in women from 1999-2000 through 2011-2012; only the latter estimate was statistically significant.

CONCLUSIONS

Our results indicate that, in women but not men, the recent secular trend in waist circumference is greater than what would be expected on the basis of changes in BMI. Possible reasons for this secular increase, along with sex differences, are uncertain.

Fruit and vegetable consumption and risk of type 2 diabetes mellitus: a dose-response meta-analysis of prospective cohort studies

BACKGROUND AND AIMS

We conducted a dose-response meta-analysis to summarize the evidence from prospective cohort studies regarding the association of fruit and vegetable consumption with risk of type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

Pertinent studies were identified by searching Embase and PubMed through June 2014. Study-specific results were pooled using a random-effect model. The dose-response relationship was assessed by the restricted cubic spline model and the multivariate random-effect meta-regression. We standardized all data using a standard portion size of 106 g. The Relative Risk (95% confidence interval) [RR (95% CI)] of T2DM was 0.99 (0.98-1.00) for every 1 serving/day increment in fruit and vegetable (FV) (P = 0.18), 0.98 (0.95-1.01) for vegetable (P = 0.12), and 0.99 (0.97-1.00) for fruit (P = 0.05). The RR (95%CI) of T2DM was 0.99 (0.97-1.01), 0.98 (0.96-1.01), 0.97 (0.93-1.01), 0.96 (0.92-1.01), 0.96 (0.91-1.01) and 0.96 (0.91-1.01) for 1, 2, 3, 4, 5 and 6 servings/day of FV (P(for non-linearity) = 0.44). The T2DM risk was 0.96 (0.95-0.99), 0.94 (0.90-0.98), 0.94 (0.89-0.98), 0.96 (0.91-1.01), 0.98 (0.92-1.05) and 1.00 (0.93-1.08) for 1, 2, 3, 4, 5 and 6 servings/day of vegetable (P(for non-linearity) < 0.01). The T2DM risk was 0.95 (0.93-0.97), 0.91 (0.89-0.94), 0.88 (0.85-0.92), 0.92 (0.88-0.96) and 0.96 (0.92-1.01) for 0.5, 1, 2, 3 and 4 servings/day of fruit (P(for non-linearity) < 0.01).

CONCLUSIONS

Two-three servings/day of vegetable and 2 servings/day of fruit conferred a lower risk of T2DM than other levels of vegetable and fruit consumption, respectively.

Evaluation of non-invasive screening measures to identify individuals with prediabetes

AIMS

Because blood-based screening to identify those with prediabetes to take part in Diabetes Prevention Program (DPP) translation efforts can be costly and time-consuming, non-invasive methods are needed. The aims of this paper are to evaluate the ability of the American Diabetes Association (ADA) risk test in identifying individuals with prediabetes, as well as the use of body composition measures for this purpose. In addition the utility of these alternate methods to ascertain the presence of the metabolic syndrome was assessed.

METHODS

Potential participants were recruited from a worksite and three community centers to take part in a DPP translation study. Participants completed onsite screening where anthropometric measures, fasting lipids and glucose, and hemoglobin A1c were assessed. Those with a BMI ≥24 kg/m(2) and prediabetes and/or the metabolic syndrome were eligible to participate. Non-invasive screening methods were evaluated for their ability to identify those with prediabetes and the metabolic syndrome based on clinically measured values.

RESULTS

All non-invasive methods were highly sensitive (68.9% to 98.5%) in the detection of prediabetes, but specificity was low (6.7% to 44.5%). None of the alternatives evaluated achieved acceptable discrimination levels in ROC analysis. Similar results were noted in identifying the metabolic syndrome.

CONCLUSIONS

The non-invasive methods evaluated in this study effectively identify participants with prediabetes, but would also allow for enrollment of a large number of individuals who do not have prediabetes. Deciding whether to use these alternatives, blood-based measures, or a combination of both will ultimately depend on the purpose of the program and the level of flexibility regarding participant eligibility.

Assessing cardiometabolic risk in middle-aged adults using body mass index and waist-height ratio: are two indices better than one? A cross-sectional study

BACKGROUND

A novel obesity classification method has been proposed using body mass index (BMI) and waist-height ratio (WHtR) together. However, the utility of this approach is unclear. In this study we compare the metabolic profiles in subjects defined as overweight or obese by both measures. We examine a range of metabolic syndrome features, pro-inflammatory cytokines, acute-phase response proteins, coagulation factors and white blood cell counts to determine whether a combination of both indices more accurately identifies individuals at increased obesity-related cardiometabolic risk.

METHODS

This was a cross-sectional study involving a random sample of 1856 men and women aged 46-73 years. Metabolic and anthropometric profiles were assessed. Linear and logistic regression analyses were used to compare lipid, lipoprotein, blood pressure, glycaemic and inflammatory biomarker levels between BMI and WHtR tertiles. Multinomial logistic regression was performed to determine cardiometabolic risk feature associations with BMI and WHtR groupings. Receiver operating characteristic curve analysis was used to evaluate index discriminatory ability.

RESULTS

The combination of BMI and WHtR tertiles identified consistent metabolic variable differences relative to those characterised on the basis of one index. Similarly, odds ratios of having cardiometabolic risk features were noticeably increased in subjects classified as overweight or obese by both measures when compared to study participants categorised by either BMI or WHtR separately. Significant discriminatory improvement was observed for detecting individual cardiometabolic risk features and adverse biomarker levels. In a fully adjusted model, only individuals within the highest tertile for both indices displayed a significant and positive association with pre-diabetes, OR: 3.4 (95 % CI: 1.9, 6.0), P < 0.001.

CONCLUSIONS

These data provide evidence that the use of BMI and WHtR together may improve body fat classification. Risk stratification using a composite index may provide a more accurate method for identifying high and low-risk subjects.

Variation in the risk of progression between glycemic stages across different levels of body mass index: evidence from a United States electronic health records system

OBJECTIVE

The purpose of this study was to assess how the risks of glycemic stage transitions observed in clinical practice vary with body mass index (BMI). These transitions included progression from euglycemia ('normal') to prediabetes (PreD) and from PreD to type 2 diabetes (T2D), as well as from normal directly to T2D, and reversions from PreD to normal.

METHODS

We examined the Geisinger Health System electronic health records and insurance claims data, segmenting a subject's medical history into normal, PreD, and/or T2D glycemic stages via diagnosis codes, glycosylated hemoglobin A1c (HbA1c) or fasting plasma glucose lab results, and use of anti-diabetic drugs. Weibull survival models, adjusted for age, gender, race, and smoking, were used to estimate the glycemic progression hazard ratios for BMI categories relative to normal BMI.

RESULTS

The sample included 32,864 adults with normal glycemic levels at baseline and 4483 with PreD. The adjusted hazard ratios for normal to PreD progression ranged from 1.8 (25 ≤ BMI < 30 kg/m(2)) to 6.5 (BMI ≥ 40 kg/m(2)); for PreD to T2D, 1.3 to 2.9; for normal to T2D, 1.8 to 9.5; and for PreD to normal, ∼0.7 across all BMI.

LIMITATIONS

The glycemic transitions may be recognized after the true onset since periodic glycemic testing was not required across the study population.

CONCLUSIONS

A positive association between the risks of progression along the glycemic continuum and BMI levels was observed in a real-world United States practice setting.

Longitudinal association of anthropometric measures of adiposity with cardiometabolic risk factors in postmenopausal women

PURPOSE

Some studies suggest that anthropometric measures of abdominal obesity may be superior to body mass index (BMI) for the prediction of cardiometabolic risk factors; however, most studies have been cross-sectional. Our aim was to prospectively examine the association of change in BMI, waist-to-hip ratio (WHR), waist circumference (WC), and waist circumference-to-height ratio (WCHtR) with change in markers of cardiometabolic risk in a population of postmenopausal women.

METHODS

We used a subsample of participants in the Women's Health Initiative aged 50 to 79 years at entry with available fasting blood samples and anthropometric measurements obtained at multiple time points over 12.8 years of follow-up (n = 2672). The blood samples were used to measure blood glucose, insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides at baseline, and at years 1, 3, and 6. We conducted mixed-effects linear regression analyses to examine associations at baseline and longitudinal associations between change in anthropometric measures and change in cardiometabolic risk factors, adjusting for covariates.

RESULTS

In longitudinal analyses, change in BMI, WC, and WCHtR robustly predicted change in cardiometabolic risk, whereas change in WHR did not. The strongest associations were seen for change in triglycerides, glucose, and HDL-C (inverse association).

CONCLUSION

Increase in BMI, WC, and WCHtR strongly predicted increases in serum triglycerides and glucose, and reduced HDL-C. WC and WCHtR were superior to BMI in predicting serum glucose, HDL-C, and triglycerides. WCHtR was superior to WC only in predicting serum glucose. BMI, WC, and WCHtR were all superior to WHR.

Body mass index and the risk of all-cause mortality among patients with type 2 diabetes mellitus

BACKGROUND

Several prospective studies have evaluated the association between body mass index (BMI) and death risk among patients with diabetes mellitus; however, the results have been inconsistent.

METHODS AND RESULTS

We performed a prospective cohort study of 19 478 black and 15 354 white patients with type 2 diabetes mellitus. Cox proportional hazards regression models were used to estimate the association of different levels of BMI stratification with all-cause mortality. During a mean follow-up of 8.7 years, 4042 deaths were identified. The multivariable-adjusted (age, sex, smoking, income, and type of insurance) hazard ratios for all-cause mortality associated with BMI levels (18.5-22.9, 23-24.9, 25-29.9, 30-34.9 [reference group], 35-39.9, and ≥40 kg/m(2)) at baseline were 2.12 (95% confidence interval [CI], 1.80-2.49), 1.74 (95% CI, 1.46-2.07), 1.23 (95% CI, 1.08-1.41), 1.00, 1.19 (95% CI, 1.03-1.39), and 1.23 (95% CI, 1.05-1.43) for blacks and 1.70 (95% CI, 1.42-2.04), 1.51 (95% CI, 1.27-1.80), 1.07 (95% CI, 0.94-1.21), 1.00, 1.07 (95% CI, 0.93-1.23), and 1.20 (95% CI, 1.05-1.38) for whites, respectively. When stratified by age, smoking status, patient type, or the use of antidiabetic drugs, a U-shaped association was still present. When BMI was included in the Cox model as a time-dependent variable, the U-shaped association of BMI with all-cause mortality risk did not change.

CONCLUSIONS

The present study indicated a U-shaped association of BMI with all-cause mortality risk among black and white patients with type 2 diabetes mellitus. A significantly increased risk of all-cause mortality was observed among blacks with BMI <30 kg/m(2) and ≥35 kg/m(2) and among whites with BMI <25 kg/m(2) and ≥40 kg/m(2) compared with patients with BMI of 30 to 34.9 kg/m(2).

Obesity indexes and total mortality among elderly subjects at high cardiovascular risk: the PREDIMED study

BACKGROUND

Different indexes of regional adiposity have been proposed for identifying persons at higher risk of death. Studies specifically assessing these indexes in large cohorts are scarce. It would also be interesting to know whether a dietary intervention may counterbalance the adverse effects of adiposity on mortality.

METHODS

We assessed the association of four different anthropometric indexes (waist-to-height ratio (WHtR), waist circumference (WC), body mass index (BMI) and height) with all-cause mortality in 7447 participants at high cardiovascular risk from the PREDIMED trial. Forty three percent of them were men (55 to 80 years) and 57% were women (60 to 80 years). All of them were initially free of cardiovascular disease. The recruitment took place in 11 recruiting centers between 2003 and 2009.

RESULTS

After adjusting for age, sex, smoking, diabetes, hypertension, intervention group, family history of coronary heart disease, and leisure-time physical activity, WC and WHtR were found to be directly associated with a higher mortality after 4.8 years median follow-up. The multivariable-adjusted HRs for mortality of WHtR (cut-off points: 0.60, 0.65, 0.70) were 1.02 (0.78-1.34), 1.30 (0.97-1.75) and 1.55 (1.06-2.26). When we used WC (cut-off points: 100, 105 and 110 cm), the multivariable adjusted Hazard Ratios (HRs) for mortality were 1.18 (0.88-1.59), 1.02 (0.74-1.41) and 1.57 (1.19-2.08). In all analyses, BMI exhibited weaker associations with mortality than WC or WHtR. The direct association between WHtR and overall mortality was consistent within each of the three intervention arms of the trial.

CONCLUSIONS

Our study adds further support to a stronger association of abdominal obesity than BMI with total mortality among elderly subjects at high risk of cardiovascular disease. We did not find evidence to support that the PREDIMED intervention was able to counterbalance the harmful effects of increased adiposity on total mortality.

TRIAL REGISTRATION

Controlled-Trials.com ISRCTN35739639.

Sex specific incidence rates of type 2 diabetes and its risk factors over 9 years of follow-up: Tehran Lipid and Glucose Study

Objective

To investigate the population-based incidence of type 2 diabetes and its potential risk factors in a sex-split cohort of Iranian population.

Materials and Methods

A total of 8400 non-diabetic participants, aged ≥20 years (3620 men and 4780 women) entered the study. Crude and age standardized incidence rates per 1000 person-years were calculated for whole population and each sex separately. Cox proportional hazard models were used to evaluate hazard ratios (HR) and 95% confidence intervals for all potential risk factors in both uni-variable and multivariable models.

Results

During a median follow-up of 9.5 years, 736 new cases of diabetes were identified, including 433 women and 303 men. The annual crude and age-standardized incidence rates (95% CI) of diabetes in the total population were 10.6 (9.92–11.4) and 9.94 (7.39–13.6) per 1000 person-years of follow-up and the corresponding sex specific rates were 10.2 (9.13–11.4) and 9.36 (5.84–14.92) in men and 11.0 (9.99–12.0) and 10.1 (7.24–13.9) in women, respectively. In the multivariable model, the risk for incident diabetes was significantly associated with fasting and 2 hour post challenge plasma glucose as well as family history of diabetes in both men and women. However, among women, only the contribution of wrist circumference to incident diabetes achieved statistical significance [HR: 1.16 (1.03–1.31)] with waist/height ratio being marginally significant [HR: 1.02 (0.99–1.04)]; while among men, only body mass index was a significant predictor [HR: 1.12 (1.02–1.22)]. Additionally, low education level conferred a higher risk for incident diabetes only among men [HR: 1.80 (1.23–2.36); P for interaction with sex = 0.003].

Conclusion

Overall, sex did not significantly modify the impact of risk factors associated with diabetes among Iranian adults; however, among modifiable risk factors, the independent role of lower education and general adiposity in men and central adiposity in women might require different preventive strategies.

Obesity and adiposity indicators, asthma, and atopy in Puerto Rican children

BACKGROUND

Whether adiposity indicators other than body mass index (BMI) should be used in studies of childhood asthma is largely unknown. The role of atopy in "obese asthma" is also unclear.

OBJECTIVES

To examine the relationship among adiposity indicators, asthma, and atopy in Puerto Rican children, and to assess whether atopy mediates the obesity-asthma association.

METHODS

In a study of Puerto Rican children with (n = 351) and without (n = 327) asthma, we measured BMI, percent of body fat, waist circumference, and waist-to-hip ratio. The outcomes studied included asthma, lung function, measures of atopy, and, among cases, indicators of asthma severity or control. We performed mediation analysis to assess the contribution of atopy to the relationship between adiposity and asthma.

RESULTS

BMI, percent of body fat, and waist circumference were associated with increased odds of asthma. Among cases, all 3 measures were generally associated with lung function, asthma severity/control, and atopy; however, there were differences depending on the adiposity indicator analyzed. Atopy considerably mediated the adiposity-asthma association in this population: allergic rhinitis accounted for 22% to 53% of the association with asthma, and sensitization to cockroach mediated 13% to 20% of the association with forced vital capacity and 29% to 42% of the association with emergency department visits for asthma.

CONCLUSIONS

Adiposity indicators are associated with asthma, asthma severity/control, and atopy in Puerto Rican children. Atopy significantly mediates the effect of adiposity on asthma outcomes. Longitudinal studies are needed to further investigate the causal role, if any, of adiposity distribution and atopy on "obese asthma" in childhood.

The association of body mass index with the risk of type 2 diabetes: a case-control study nested in an electronic health records system in the United States

OBJECTIVES

Obesity is a known risk factor for type 2 diabetes (T2D). We conducted a case-control study to assess the association between body mass index (BMI) and the risk of being diagnosed with T2D in the United States.

METHODS

We selected adults (≥ 18 years old) who were diagnosed with T2D (defined by ICD-9-CM diagnosis codes or use of anti-diabetic medications) between January 2004 and October 2011 ("cases") from an electronic health records database provided by an integrated health system in the Middle Atlantic region. Twice as many individuals enrolled in the health system without a T2D diagnosis during the study period ("controls") were selected based on age, sex, history of cardiac comorbidities or hyperinflammatory state (defined by C-reactive protein and erythrocyte sedimentation rate), and use of psychiatric or beta blocker medications. BMI was measured during one year prior to the first observed T2D diagnosis (for cases) or a randomly assigned date (for controls); individuals with no BMI measure or BMI < 18.5 kg/m2 were excluded. We assessed the impact of increased BMI (overweight: 25-29.9 kg/m2; Obesity Class I: 30-34.9 kg/m2; Obesity Class II: 35-39.9 kg/m2; Obesity Class III: ≥40 kg/m2), relative to normal BMI (18.5-24.9 kg/m2), on a T2D diagnosis using odds ratios (OR) and relative risks (RR) estimated from multiple logistic regression results.

RESULTS

We included 12,179 cases (mean age: 55, 43% male) and 25,177 controls (mean age: 56, 45% male). We found a positive association between BMI and the risk of a T2D diagnosis. The strength of this association increased with BMI category (RR [95% confidence interval]: overweight, 1.5 [1.4-1.6]; Obesity Class I, 2.5 [2.3-2.6]; Obesity Class II, 3.6 [3.4-3.8]; Obesity Class III, 5.1 [4.7-5.5]).

CONCLUSIONS

BMI is strongly and independently associated with the risk of being diagnosed with T2D. The incremental association of BMI category on the risk of T2D is stronger for people with a higher BMI relative to people with a lower BMI.

Chronic weight dissatisfaction predicts type 2 diabetes risk: aerobic center longitudinal study

OBJECTIVE

Weight dissatisfaction, defined as discordance between actual and goal weight, may be associated with increased risk for several obesity-related comorbidities. The purpose of the study was to examine the association between weight dissatisfaction and risk of developing Type 2 diabetes.

METHOD

This longitudinal study used data from 9,584 adults enrolled in the Aerobics Center Longitudinal Study. Key variables included multiple measures of measured weight, self-reported goal weight, and incident diabetes. Weight dissatisfaction was defined as being above the median of measured weight minus goal weight. Cox proportional hazards regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for diabetes incidence by weight dissatisfaction.

RESULTS

HRs for time until diabetes diagnosis revealed that family history of diabetes (HR = 1.46, 95% CI [1.13, 1.90]), age (HR = 1.03, 95% CI [1.02, 1.04]), and weight dissatisfaction (HR = 1.83, 95% CI [1.50, 2.25]) at baseline were statistically significant predictors. Longitudinally, higher risk was observed in individuals who either stayed dissatisfied (HR = 2.98, 95% CI [1.98, 4.48]) or became dissatisfied (HR = 1.51, 95% CI [0.79, 2.89]), compared with those who stayed satisfied. After additional adjustment for BMI, the elevated HR for those who remained dissatisfied compared with those who remained satisfied persisted (HR = 2.85, 95% CI [1.89, 4.31]).

CONCLUSIONS

Weight dissatisfaction, regardless of BMI, represents a potentially important psychophysiological modifier of the relationships between BMI and risk of Type 2 diabetes, and warrants greater attention in future studies of chronic disease risk.

Employment status, depressive symptoms, and waist circumference change in midlife women: the Study of Women's Health Across the Nation (SWAN)

PURPOSE

Changes in employment status have shown inconsistent associations with adiposity. This study tested whether the presence of elevated depressive symptoms explains variability in the time-varying association between employment status and central adiposity.

METHOD

Employment status, depressive symptoms, and waist circumference (WC) were assessed annually over 10 years in a multiethnic sample of 3220 midlife women enrolled in the Study of Women's Health Across the Nation. Linear mixed-effects models tested time-varying associations of employment status, depressive symptoms, and their interaction with WC.

RESULTS

WC increases were greatest during the years of combined nonemployment and elevated depressive symptoms (1.00 cm/y) and lowest in the years of full-time employment and elevated depressive symptoms (0.25 cm/y), compared with the years of full-time employment and nonelevated depressive symptoms (0.51 cm/y). Employment status was unrelated to WC in years without elevated depressive symptoms. The pattern of results was unchanged when analyses were restricted to preretirement observations and did not vary according to WC at baseline or ethnicity/race.

CONCLUSIONS

Identifying and managing depressive symptoms in midlife women who are not working may help prevent increases in central adiposity.

Diabetes and risk of Parkinson's disease: an updated meta-analysis of case-control studies

BACKGROUND

Whether diabetes increases the risk of Parkinson's disease (PD) is still inconclusive. The objective of this updated meta-analysis is to synthesize evidence from case-control studies that evaluated the association between diabetes and the risk of PD.

METHODS

Seven databases were searched to identify case-control studies that evaluated the association between diabetes and PD. The methodological quality of included studies was assessed using Newcastle-Ottawa scale. All data were analyzed using Review Manager 5.1 software. Subgroup analyses were also adopted, according to stratification on gender, geographic location, source of the control group, smoking, anti-diabetes drug prescription and duration of DM.

RESULTS

Fourteen studies fulfilled inclusion criteria for meta-analysis, yielding a total of 21395 PD patients and 84579 control subjects. Individuals with diabetes were found to have a negative association with future PD (OR 0.75; 95% CI 0.58-0.98) in spite of significant heterogeneity. In subgroup analyses, the negative correlation was still found in studies from North America, non-PD control groups from general population, never smoking individuals, and DM ascertainment based on questionnaire or self-report. Stratification of gender and DM duration showed no significant association. No association was also found in European and Asian individuals, hospital-based controls, ever smoking subjects, DM assessment by medical record or physician diagnosis, and insulin prescription for DM.

CONCLUSION

Evidence from case-control studies suggested that diabetic individuals may have a decreased incidence of PD despite significant heterogeneity. More researches are warranted to clarify an understanding of the association between diabetes and risk of PD.

Youth, caregiver, and prescriber experiences of antipsychotic-related weight gain

Objectives. To explore the lived experience of youth, caregivers, and prescribers with antipsychotic medications. Design. We conducted a qualitative interpretive phenomenology study. Youth aged 11 to 25 with recent experience taking antipsychotics, the caregivers of youth taking antipsychotics, and the prescribers of antipsychotics were recruited. Subjects. Eighteen youth, 10 caregivers (parents), and 11 prescribers participated. Results. Eleven of 18 youth, six of ten parents, and all prescribers discussed antipsychotic-related weight gain. Participants were attuned to the numeric weight changes usually measured in pounds. Significant discussions occurred around weight changes in the context of body image, adherence and persistence, managing weight increases, and metabolic effects. These concepts were often inextricably linked but maintained the significance as separate issues. Participants discussed tradeoffs regarding the perceived benefits and risks of weight gain, often with uncertainty and inadequate information regarding the short- and long-term consequences. Conclusion. Antipsychotic-related weight gain in youth influences body image and weight management strategies and impacts treatment courses with respect to adherence and persistence. In our study, the experience of monitoring for weight and metabolic changes was primarily reactive in nature. Participants expressed ambiguity regarding the short- and long-term consequences of weight and metabolic changes.

Predicting cardiometabolic risk: waist-to-height ratio or BMI. A meta-analysis

BACKGROUND AND OBJECTIVES

The identification of increased cardiometabolic risk among asymptomatic individuals remains a huge challenge. The aim of this meta-analysis was to compare the association of body mass index (BMI), which is an index of general obesity, and waist-to-height ratio (WHtR), an index of abdominal obesity, with cardiometabolic risk in cross-sectional and prospective studies.

METHODS

PubMed and Embase databases were searched for cross-sectional or prospective studies that evaluated the association of both BMI and WHtR with several cardiometabolic outcomes. The strength of relative risk (RR) with 95% confidence interval (CI) was calculated using the optimal cutoffs of BMI and WHtR in cross-sectional studies, while any available cutoff was used in prospective studies. The pooled estimate of the ratio of RRs (rRR [=RRBMI/RRWHtR]) with 95% CIs was used to compare the association of WHtR and BMI with cardiometabolic risk. Meta-regression was used to identify possible sources of heterogeneity between the studies.

RESULTS

Twenty-four cross-sectional studies and ten prospective studies with a total number of 512,809 participants were identified as suitable for the purpose of this meta-analysis. WHtR was found to have a stronger association than BMI with diabetes mellitus (rRR: 0.71, 95% CI: 0.59-0.84) and metabolic syndrome (rRR: 0.92, 95% CI: 0.89-0.96) in cross-sectional studies. Also in prospective studies, WHtR appears to be superior to BMI in detecting several outcomes, including incident cardiovascular disease, cardiovascular disease mortality, and all-cause mortality. The usefulness of WHtR appears to be better in Asian than in non-Asian populations. BMI was not superior to WHtR in any of the outcomes that were evaluated. However, the results of the utilized approach should be interpreted cautiously because of a substantial heterogeneity between the results of the studies. Meta-regression analysis was performed to explain this heterogeneity, but none of the evaluated factors, ie, sex, origin (Asians, non-Asians), and optimal BMI or WHtR cutoffs were significantly related with rRR.

CONCLUSION

The results of this meta-analysis support the use of WHtR in identifying adults at increased cardiometabolic risk. However, further evidence is warranted because of a substantial heterogeneity between the studies.