Body Mass Index and the Risk of Hypertension-Diabetes Comorbidity in Elderly Population: A Prospective Cohort in...

Body mass index (BMI) is closely linked to hypertension and diabetes mellitus (DM). However, the association between BMI and hypertension-diabetes comorbidity in elderly population of China remains uncertain.

This cohort study was conducted based on a prospective database of Chinese Longitudinal Healthy Longevity Survey (CLHLS). The primary outcome was hypertension-diabetes comorbidity. The secondary outcomes included hypertension and DM. BMI was categorized into four groups according to Chinese guidelines: underweight (BMI < 18.5 kg/m²), normal weight (BMI 18.5-23.9 kg/m²), overweight (BMI 24.0-27.9 kg/m²), and obesity (BMI ≥ 28.0 kg/m²).

The final analysis included 5,342 individuals for hypertension, 6,335 for DM, and 6,414 for hypertension-diabetes comorbidity (all individuals aged 65 years and above). Cox regression analysis of the hypertension-diabetes comorbidity revealed the adjusted hazard ratio (HR) for the underweight group was 0.747 (95% confidence interval [CI], 0.651-0.857), for the overweight group was 1.517 (95% CI, 1.309-1.758), and for the obesity group was 1.620 (95% CI, 1.237-2.121) comparing with normal weight group (reference). When considering BMI as a continuous variable, the adjusted HR was 1.043 (95% CI, 1.029-1.059). Employing a multi-model adjusting strategy based on the directed acyclic graph, the HR for individuals with BMI ≥ 24.0 (versus BMI < 24.0) was 1.486 (95% CI, 1.301-1.698). Restricted cubic splines indicate a positive linear trend between BMI (range in BMI ≥ 24) and the risk of hypertension-diabetes comorbidity. The relationship between BMI and secondary outcomes exhibited results similar to those of the primary outcome.Additionally, compared to the Han ethnic, other ethnic had a significantly lower risk of the primary outcome, with an adjusted HR of 0.334 (95% CI, 0.235-0.475). Similar findings were observed for the secondary outcomes.

Increased BMI is significantly associated with a higher risk of hypertension-diabetes comorbidity, hypertension, and DM in elderly population of China. Additionally, Han participants (versus non-Han) have a notably greater risk of developing hypertension-diabetes comorbidity, hypertension, and DM. Greater attention should be paid to obesity in elderly Han Chinese individuals, given its significant associated disease burden.