Using Different Anthropometric Indices To Predict Risk Of Type2 Diabetes And Hypertension In Elderly Population

With the development of society and economy,the incidence of chronic non-communicable diseases(NCDs)was rising gradually.Diabetes has become a serious public health problem threatening human health all over the world.In China,the prevalence of diabetes is estimated to be higher than 11.6% and more than 100 million adults were affected.Hypertension is an important risk factor for cardiovascular and cerebrovascular diseases.The prevalence of hypertension in China was about 29.6%.Obesity plays an important role in the development of type 2 diabetes and hypertension.In epidemiological studies,traditional anthropometric indices body mass index(BMI)has been used to evaluate general obesity,waist circumference(WC)and waist-to-height ratio(WHt R)to evaluate abdominal obesity.However,these indices could not discriminate visceral fat from subcutaneous fat so that novel anthropometric indices,such as visceral adiposity index(VAI),a body shape index(ABSI),and body roundness index(BRI)have been proposed to be alternative indicators of obesity.VAI,an indicator of visceral fat dysfunction and insulin sensitivity,was calculated with the BMI,WC,TG and HDL-c.A higher ABSI represented that the individuals' WC was higher than the WC responded to given height and weight,which indicated that more fat was accumulated in abdomen.What's more,China has become an aging society,there will be 40 million people aged 60 years or older in 2050,accounting for 30% of the population.Aging not only promotes increased body fat,but also changes its distribution.At present,studies about novel anthropometric indices and NCDs were mainly cross-sectional,lack of prospective study in Chinese,especially in the elderly.Therefore,in the present study,we aim to examine the associations of different anthropometric indices with type 2 diabetes and hypertension risk and to investigate whether these novel anthropometric indices could improve predictive ability beyond traditional indices in elderly population.The present study includes the following two parts:Part ?: Using different anthropometric indices to predict risk of type 2 diabetes in elderly population Objective: To examine the associations of different anthropometric indices with incident diabetes risk and whether novel anthropometric indices improve diabetes prediction beyond traditional indices among elderly Chinese.Methods: There were 9962 elderly individuals(age ? 60)derived from the prospective Dongfeng-Tongji cohort.Hazard ratio(HR)and corresponding 95% confidence interval(CI)were evaluated by Cox proportional hazard model to examine the associations between traditional anthropometric indices BMI,WC,WHt R,novel anthropometric indices VAI,ABSI,BRI and diabetes risk.Receiver operating characteristic(ROC)curve and area under curve(AUC)were applied to compare the novel anthropometric indices with the traditional indices in diabetes prediction.Results: During mean 4.6 years of follow-up,614 incident cases of type 2 diabetes(T2D)were identified.Significant positive associations were detected between BMI,WC,WHt R,VAI,BRI and incident T2 D.ABSI was inversely associated with T2 D risk.BMI was the strongest predictor in diabetes in men(AUC=0.655)comparable with the other anthropometric indices(P < 0.05).Similar as men,BMI was the strongest predictor(AUC=0.635)in women.Except for WC,the AUC of BMI was larger than WHt R,VAI,and BRI.In contrast,ABSI was not a good predictor in both men(AUC=0.507)and women(AUC=0.503).Conclusions: In elderly population,BMI,WC,WHt R,VAI and BRI were positively associated with incident T2 D.Among them,BMI was the strongest predictor in both men and women.Part II Using different anthropometric indices to predict risk of hypertension in elderly population Objective: To examine the associations of different anthropometric indices with incident hypertension among the elderly population.A risk score model was developed to predict incident hypertension,and anthropometric indices were added to the model to examine whether novel anthropometric indices improve hypertension prediction beyond traditional indices among elderly Chinese.Methods: There were 6478 elderly individuals(age ? 60)derived from the prospective Dongfeng-Tongji cohort.Odd ratio(OR)and corresponding 95% confidence interval(CI)were evaluated by logistic regression model to examine the associations between traditional anthropometric indices BMI,WC,WHt R,novel anthropometric indices VAI,ABSI,BRI and hypertension risk.A hypertension prediction model was developed and anthropometric indices were added to the model.Receiver operating characteristic(ROC)curve and area under curve(AUC)were applied to compare the prediction ability of the models.Results: In the study,1787 incident hypertension was diagnosed.Significant positive associations were detected between BMI,WC,WHt R,VAI,BRI and incident hypertension risk,after adjustment for potential confounders including age,smoking,drinking,physical activity,education,hyperlipidemia(except VAI)and family history of hypertension.There is no statistical significance between ABSI and hypertension.The basic hypertension prediction model included age,drinking(only in men),education status(only in men),systolic blood pressure(SBP),diastolic blood pressure(DBP),and fasting blood glucose(FBG)levels.Based on the basic predictive model,BMI and BRI(only in men)improved area under curve(AUC)significantly(P <0.05).BMI was the strongest predictor in both men(AUC = 0.697)and women(AUC = 0.685)in the extended model.Conclusions: Significant positive associations were detected between BMI,WC,WHt R,VAI and BRI and incident hypertension risk among elderly Chinese.BMI was the strongest predictor in hypertension prediction compared with other anthropometric indices.