Obesity indices and the risk of total and cardiovascular mortality among people with diabetes: a long-term follow-up study in Taiwan

BACKGROUND

The association between obesity indicators and mortality in individuals with diabetes remains unclear, and data on cardiovascular mortality are scarce. Therefore, we investigated the associations between the five adiposity indices and both all-cause and cardiovascular mortality in patients with diabetes.

METHODS

This cohort study included 34,686 adults with diabetes who underwent a standard health-screening program between 1996 and 2017 in Taiwan. The dates and causes of death till January 2022 were retrieved from the National Death Registry. Cox proportional hazards models were used to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for all-cause and cardiovascular mortality in relation to body mass index (BMI), waist circumference, waist-hip ratio (WHR), body fat percentage (BF%), and A Body Shape Index (ABSI), using the third quintile as the reference group.

RESULTS

During a median follow-up of 15 years, there were 8,324 deaths, of which 1,748 were attributed to cardiovascular disease. After adjusting for demographics, lifestyle factors and comorbidities, ABSI was associated with all-cause mortality in an exposure-response manner; the HR (95% CI) for first and fifth vs. third quintile was 0.78 (0.69-0.89) and 1.24 (1.14-1.35), respectively. A similar but weaker exposure-response relationship was found between WHR and mortality. People with a lower BMI and BF% had an increased risk of mortality (HR [95% CI] for the first vs. third quintiles, 1.33 [1.22, 1.44] and 1.42 [1.30, 1.56], respectively). No association was observed between waist circumference categories and risk of mortality. Similar results were observed for the association of BF%, waist circumference, and ABSI with cardiovascular mortality. However, no significant association was observed between BMI and cardiovascular mortality. The association between WHR and cardiovascular mortality was stronger than that between WHR and all-cause mortality.

CONCLUSIONS

ABSI demonstrated a consistent exposure-response relationship with both all-cause and cardiovascular mortality in this Asian cohort with diabetes. Our findings highlight the importance of monitoring ABSI, a surrogate index of central adiposity, in patients with diabetes.

Association of decreases in PM2.5 levels due to the implementation of environmental protection policies with the incidence of obesity in adolescents: A prospective cohort study

AIMS

To explore the association between decreased levels of particulate matter (≤2.5 µm; PM_2.5) due to the implementation of environmental protection policies and the incidence of obesity in adolescents in Chongqing, China through a prospective cohort study.

METHODS

A total of 2105 children (52.02% male; aged 7.33 ± 0.60 years at baseline) were enrolled from the Chongqing Children's Health Cohort. A mixed linear regression model was used to analyse the relationships of PM_2.5 levels with obesity indicators after adjusting for covariates. Additionally, a Poisson regression model was used to determine the relationship between PM_2.5 exposure and the incidence of overweight/obesity.

RESULTS

The average PM_2.5 exposure levels from participant conception to 2014, from 2015 to 2017, and from 2018 to 2019 were 66.64 ± 5.33 μg/m³, 55.49 ± 3.78 μg/m³, and 42.50 ± 1.87 μg/m³, respectively; these levels significantly decreased over time (P < 0.001). Throughout the entire follow-up period, the incidence of overweight/obesity after a ≥ 25 μg/m³ decrease in the PM_2.5 level was 4.57% among females; this incidence was the lowest among females who experienced remarkable decreases in PM_2.5 exposure. A 1-µg/m³ decrease in the PM_2.5 level significantly decreased the body mass index (BMI), BMI z score (BMI_z), and weight of adolescents (all P < 0.001). Compared with a < 20-μg/m³ decrease in the PM_2.5 level, a ≥ 25-μg/m³ decrease protected against increased BMI (net difference= -0.93; 95% confidence interval [CI]: (-1.23,-0.63) kg/m²), BMI_z (-0.28 (-0.39, -0.17)), weight (-1.59 (-2.44, -0.74) kg), and incidence of overweight/obesity (0.48 (0.37, 0.62), P < 0.001). Moreover, compared with a < 20-μg/m³ decrease in the PM_2.5 level, a ≥ 25-μg/m³ decrease resulted in significant absolute differences in BMI (-1.26 (-1.56, -0.96) kg/m²), BMI_z (-0.53 (-0.65, -0.40)) and weight (-3.01 (-3.8, -2.19) kg) (all P < 0.001).

CONCLUSIONS

This study showed the etiological relevance of declining PM_2.5 concentrations for the incidence of obesity in children and adolescents, suggesting that controlling ambient air pollutants may prevent the development of obesity in this age group. Continuous implementation of environmental protection policies in China has led to substantial health benefits.

Influence of Changes in Obesity Indicators on the Risk of Hypertension: A Cohort Study in Southern China

OBJECTIVES

The objective of this study was to demonstrate the association between changes in different obesity indicators and the risk of incident hypertension by the age-group among community-dwelling residents in southern China.

METHODS

A total of 6,959 non-hypertensive participants aged ≥18 years old were enrolled in this cohort study and completed questionnaire interviews and anthropometric measurements at baseline (2010) and follow-up (2017). A time-dependent covariate Cox proportional hazard model considered the changes in obesity indicators during the follow-up period and calculated the hazard ratios (HRs) to analyze the risk of incident hypertension according to different obesity indicators.

RESULTS

During a mean follow-up of 7.1 years, 1,904 participants were newly diagnosed with hypertension. The body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were significantly positively associated with an increased future risk of incident hypertension, and BMI was the best predictive indicator of hypertension (obesity in men: HR = 2.65, 95% confidence interval (CI) = 2.20-3.20; obesity in women: HR = 2.80, 95% CI = 2.27-3.45). Compared with the middle-aged and older group, the risk of incident hypertension was highest in the younger group which had the highest baseline obesity indicators.

CONCLUSIONS

Changes in obesity indicators were significantly associated with the risk of incident hypertension in all age-groups, and the risk of future incident hypertension increased with the increase in baseline obesity indicators.

Obesity indicators that best predict type 2 diabetes in an Indian population: insights from the Kerala Diabetes Prevention Program

Obesity indicators are known to predict the presence of type 2 diabetes mellitus (T2DM); however, evidence for which indicator best identifies undiagnosed T2DM in the Indian population is still very limited. In the present study we examined the utility of different obesity indicators to identify the presence of undiagnosed T2DM and determined their appropriate cut point for each obesity measure. Individuals were recruited from the large-scale population-based Kerala Diabetes Prevention Program. Oral glucose tolerance tests was performed to diagnose T2DM. Receiver operating characteristic (ROC) curve analyses were used to compare the association of different obesity indicators with T2DM and to determine the optimal cut points for identifying T2DM. A total of 357 new cases of T2DM and 1352 individuals without diabetes were identified. The mean age of the study participants was 46⋅4 (sd 7⋅4) years and 62 % were men. Waist circumference (WC), waist:hip ratio (WHR), waist:height ratio (WHtR), BMI, body fat percentage and fat per square of height were found to be significantly higher (P < 0⋅001) among those with diabetes compared with individuals without diabetes. In addition, ROC for WHR (0⋅67; 95 % 0⋅59, 0⋅75), WHtR (0⋅66; 95 % 0⋅57, 0⋅75) and WC (0⋅64; 95 % 0⋅55, 0⋅73) were shown to better identify patients with T2DM. The proposed cut points with an optimal sensitivity and specificity for WHR, WHtR and WC were 0⋅96, 0⋅56 and 86 cm for men and 0⋅88, 0⋅54 and 83 cm for women, respectively. The present study has shown that WHR, WHtR and WC are better than other anthropometric measures for detecting T2DM in the Indian population. Their utility in clinical practice may better stratify at-risk patients in this population than BMI, which is widely used at present.

Cardiac autonomic function and its association with cardiometabolic disease risk factors in Black South African children

OBJECTIVE

This study evaluated the associations between cardiac autonomic nervous system (ANS) activity and cardiometabolic disease (CMD) risk factors among black South African children.

DESIGN

The participants included 34 black South African children (11.85 ± 0.89 y). CMD risk factors included waist circumference (WC), hip circumference (HC), body mass index z-score (BMI z-score), blood pressure (SBP, DBP), total cholesterol (TC), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), fasting glucose (FG), fasting insulin (FINS), and vessel stiffness index (SI). Heart rate variability was used to quantify cardiac ANS activity.

RESULTS

lnRMSSD, pNN50 and lnSD1 were inversely associated with FINS (r = -0.33, p = 0.05; r = -0.36, p = 0.03; r = -0.41, p = 0.01), WC (r = -0.45, p = 0.01; r = -0.39, p = 0.02; r = -0.45, p = 0.01), and HC (r = -0.41, p = 0.01; r = -0.36, p = 0.03; r = -0.43, p = 0.01). HDL was positively associated with lnRMSSD (r = 0.37; p = 0.03) and lnSD1 (r = 0.37; p = 0.03) while, LDL was negatively associated with HF (r = -0.41; p = 0.01). Regression analysis identified WC as the primary predictor for parasympathetic modulation in time domain (lnRMSSD: r2 = 0.21, p = 0.01; pNN50: r2 = 0.18, p = 0.01) and non-linear domain (lnSD1: r2 = 0.21, p = 0.01).

CONCLUSION

Elevated resting parasympathetic activity in children is associated with lower CMD risk factors and an elevation in the protective HDL.

Ethnicity-specific cut-offs that predict co-morbidities: the way forward for optimal utility of obesity indicators.J Biosoc Sci. 2019;51:624-626. [PMID: 30944046 DOI: 10.1017/S0021932019000178]

Obesity indicators are useful clinical tools in the measurement of obesity, but it is important for clinicians to appropriately interpret their values in individuals with different ethnicities. Future research is needed to identify optimal cut-offs that can predict the occurrence of cardio-metabolic comorbidities in individuals of different ethnic descent. Assessment of more recently developed indicators like the Edmonton Obesity Staging System and visceral adipose tissue are able to appropriately identify metabolically at-risk individuals.

Lowered cutoff points of obesity indicators are better predictors of hypertension and diabetes mellitus in premenopausal Taiwanese women

INTRODUCTION

In previous study, we found that in order to prevent MS in women aged <65 years, the cutoff points of obesity indicators should be lowered.

OBJECTIVE

To investigate whether our proposed cutoff points of obesity indicators predict the occurrence of hypertension (HT), diabetes mellitus (DM), and hyperlipidemia in premenopausal women with greater sensitivity and specificity compared to reference cutoff points of obesity that are currently being used.

METHODS

Using the database of the "2002 Survey on the Prevalence of Hypertension, Hyperglycemia and Hyperlipidemia in Taiwan" provided by the Bureau of Health Promotion, Taiwan as research material, data from 2270 premenopausal women aged 20-65 years were used for the analyses. The receiver-operating characteristic curves (ROC) of the body-mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were used to predict HT, DM, and hyperlipidemia.

RESULTS

Obesity is not a good predictor of the occurrence of hyperlipidemia in premenopausal women aged <65 years. However, our proposed cutoff points had greater sensitivity and specificity than did the reference cutoff points. To prevent the risk of HT and DM in premenopausal women, the cutoff points of obesity indicators should be reduced. The proposed values are as follows: a WHR of 0.79; a WC of 74.7 cm; a WHtR of 0.49; and a BMI of 22.3 kg/m(2).

The Use of Obesity Indicators for the Prediction of Hypertension Risk among Youth in the United Arab Emirates

BACKGROUND

Obesity is a significant risk factor for metabolic disorders including increase in blood pressure. Body mass index (BMI), waist circumference (WC) and Waist/Hip ratio (WHR) are simple and effective indicators of obesity. The objectives of this study were to examine the relationships between obesity anthropometric indicators and hypertension and to identify the best anthropometric indicator/s that can predict hypertension risk among youth in the UAE.

METHODS

A 110 first year students in a Medical University in Ajman, UAE, during the year 2009-2010 were included in a cross-sectional study. The height, weight, WC, hip circumference and blood pressure were measured and the BMI and WHR were calculated for each student and used in the analyses.

RESULTS

The mean values for BMI, WC, hip circumference and WHR, were significantly higher in the Pre/Hypertensive group compared to normal blood pressure group. The risk of Pre/ hypertension was significantly increased by 4.3 times for participants who had general obesity (BMI≥ 30) or abdominal obesity (identified from high WC). Highly significant correlations were noticed between systolic and diastolic blood pressure and all anthropometric indicators except that for Hip circumference and systolic blood pressure. Step-wise linear regression model showed that when all obesity indicators were studied together, the waist circumference was the only indicator which showed significant relationship with both systolic and diastolic blood pressure.

CONCLUSION

Waist circumference is the best anthropometric indicator that can predict hypertension risk among youth in the UAE.