Body Mass Index and the Risk of All-Cause Mortality Among Patients With Type 2 Diabetes Mellitus

Abstract

Background Several prospective studies have evaluated the association between body mass index (BMI) and death risk among patients with diabetes; however, the results have been inconsistent. Methods and Results We performed a prospective cohort study of 19,478 African American and 15,354 white patients with type 2 diabetes. 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, 4,042 deaths were identified. The multivariable-adjusted (age, sex, smoking, income and type of insurance) hazard ratios (HRs) 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/m2) at baseline were 2.12 (95% confidence interval [CI] 1.80–2.49), 1.74 (1.46–2.07), 1.23 (1.08–1.41), 1.00, 1.19 (1.03–1.39), and 1.23 (1.05–1.43) for African Americans, and 1.70 (1.42–2.04), 1.51 (1.27–1.80), 1.07 (0.94–1.21), 1.00, 1.07 (0.93–1.23), and 1.20 (1.05–1.38) for whites, respectively. When stratified by age, smoking status, patient types or use of anti-diabetic 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 current study indicated a U-shaped association of BMI with all-cause mortality risk among African American and white patients with type 2 diabetes. A significantly increased risk of all-cause mortality was observed among African Americans with BMI<30 kg/m2 and BMI ≥35 kg/m2, and among whites with BMI<25 kg/m2 and BMI ≥40 kg/m2 compared with patients with BMI 30–34.9 kg/m2.

Nonlinear association of BMI with all-cause and cardiovascular mortality in type 2 diabetes mellitus: a systematic review and meta-analysis of 414,587 participants in prospective studies

“…2 Relationship between BMI and all-cause mortality for (a) both sexes, (b) men and (c) women. Grey shading indicates 95% CI smokers in both Black and White participants [41]. In comparison Jackson and colleagues did not find a variation in the association between BMI and mortality by smoking status [30].…”

“…1). Following detailed assessments, and after the inclusion of three articles identified from manual searches, 21 articles were included in the quantitative analysis (21 studies and 24 unique cohorts; Table 1) [7,8,11,15,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. Study characteristics and the NOS scores are provided in ESM Tables 1-3.…”

Association of body mass index with all-cause mortality in patients with diabetes: a systemic review and meta-analysis

“…Besides CVD, obesity paradox has been found in different clinical situations, such as end stage renal disease (5), advanced cancer (6), and also in patients with diabetes, which has been regarded as the coronary heart disease equivalent. The relationship between BMI and mortality in patients with diabetes has revealed various results in previous prospective studies, including a U-shaped or J-shaped association (7,8) or no clear relationship (9,10). Despite the obesity paradox in patients with CVD has been confirmed previously (11,12), this phenomenon in diabetes remains controversy since the etiology of diabetes development in different BMI category is probably not the same.…”

“…Overall, 16 cohort studies with a total number of 385,925 patients were included in the analysis (6)(7)(8)(9)(10)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Study design, patients' characteristics, mean follow-up years, BMI category and its effect on mortality are summarized in Table 1.…”

“…The mean follow-up period was from 2.7 years (23) to 16 years (22). In all studies, the HRs were obtained by the adjustments for traditional vascular risk factors, and in some studies, the HRs were additionally controlled for other confounding factors, such as duration of diabetes (6,16,17,21,22,24,25), diabetic complications (9,21), menopause status (7,18), comorbid condition (16,18), and glomerular filtration rate (10).…”