BackgroundGiven the fat redistribution in later stages of life, how the associations between abdominal obesity and the risk of morbidity and mortality have changed with age have not been elucidated, especially for waist to height ratio (WHtR).ObjectiveTo compare the strength of association between obesity indices and chronic diseases at baseline, and the subsequent mortality risk among US adults.MethodsWe included 21 109 participants from National Health and Nutrition Examination Survey 1999–2014. We performed logistic regression and receiver operating curve analysis to examine the discriminatory power of obesity indicators on cardiometabolic diseases and cancer at baseline. Sex-stratified and age-stratified Cox models were constructed to explore the prospective association between obesity indices and all-cause, cardiovascular and cancer mortality.ResultsElevated WHtR, elevated waist circumference (WC) and body mass index (BMI)-classified obesity are associated with higher odds of hypertension (OR: 1.37-2.13), dyslipidemia (OR: 1.06 to 1.75, all p<0.05) and diabetes (OR: 1.40-3.16, all p<0.05). WHtR had significantly better discriminatory power to predict cardiometabolic health than BMI, especially for diabetes (area under the curve: 0.709 vs 0.654). After multivariable adjustment, all obesity indicators are associated with lower risk of all-cause mortality among females aged ≥65 years (HR: 0.64 to 0.85), but the association was only significant for BMI when obesity indicators were mutually adjusted (HR: 0.79).ConclusionsWHtR and WC appeared to be the better indicators for cardiometabolic health than BMI. However, BMI had a stronger and inverse association with a greater risk of all-cause mortality among older females.

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Background The link between total cholesterol (TC) and all-cause and specific mortality has not been elucidated. Herein, we aimed to evaluate the effect of TC levels on all-cause, cardiovascular disease (CVD), and cancer mortality. Methods All data analyzed were obtained from the National Health and Nutrition Examination Survey 1999–2014. The relationship between levels of TC and mortality was determined through Cox proportional hazard regression analysis coupled with multivariable adjustments. Two-piecewise linear regression models and Cox models with penalized splines were applied to explore nonlinear and irregular shape relationships. Kaplan–Meier survival curve and subgroup analyses were conducted. Results The sample studied comprised 14,662 men and 16,025 women, categorized as 25,429 adults aged 18–65 and 5,258 adults over 65 years old. A total of 2,570 deaths were recorded. All-cause, cardiovascular, and cancer mortality showed U-curve associations after adjusting for confounding variables in the restricted cubic spline analysis. Hazard ratios (HRs) of all-cause and cancer mortality were particularly negatively related to TC levels in the lower range < 200 mg/dL, especially in the range < 120 mg/dL (HR 1.97; 95% CI 1.38, 2.83, HR 2.39; 95% CI 1.21, 4.71, respectively). However, the HRs of cardiovascular disease mortality in the range < 120 mg/dL were the lowest (HR 0.60; 95% CI 0.15, 2.42). In the upper range, a TC range of ≥ 280 mg/dL was correlated with mortality as a result of CVD and cancer (HR 1.31; 95% CI 0.87, 1.97 and HR 1.22; 95% CI 0.82, 1.79). The lowest cumulative survival rate of all-cause mortality was recorded in the lowest TC-level group, while the lowest cumulative survival rate of CVD mortality was recorded in the highest TC-level group. Conclusions A nonlinear association of TC level with all-cause, cancer, and CVD mortality in the American population was observed, suggesting that too low or too high serum total cholesterol levels might correlate with adverse outcomes.