Association between body mass index and chronic metabolic diseases in Chinese aged population

Abstract

Objective·To evaluate the relationship between body mass index (BMI) and chronic metabolic diseases.Methods·The elderly (≥60 years old) who were underwent physical examination in the Physical Examination Center of Renji Hospital, Shanghai Jiao Tong University School of Medicine from 2014 to 2021 were studied. Their results of biochemical indicators were collected. Their height, body weight, and blood pressure were measured by trained nurses. The history of chronic metabolic diseases was collected by self-reported questionnaire. Systolic blood pressure ≥140 mmHg (1 mmHg=0.133 kPa), diastolic blood pressure ≥90 mmHg, or self-reported hypertension history was defined as hypertension. Fasting blood glucose ≥7.0 mmol/L or self-reported history of diabetes was defined as diabetes. Total cholesterol≥6.2 mmol/L, triglyceride≥2.3 mmol/L, or self-reported history of dyslipidemia was defined as dyslipidemia. The relationship between BMI and hypertension, diabetes, and dyslipidemia was evaluated by using receiver operator characteristic (ROC) curve analysis and binary logistic regression.Results·Data of 59 083 subjects were collected [30 807 men and 28 276 women, average age: (67.9±6.3) years old]. The prevalence of hypertension, diabetes and dyslipidemia was 76.5% (45 219/59 083), 24.1% (14 225/59 083) and 50.0% (29 544/59 083), respectively. Compared to the elderly people aged 60‒74 years, those aged 75 years and above had a higher proportion of hypertension and diabetes, and a lower proportion of dyslipidemia and no metabolic abnormalities. With ROC analysis, the BMI cut-off values for hypertension, diabetes, and dyslipidemia were 24.3, 23.9, and 23.9 kg/m2. The BMI cut-off values for hypertension and diabetes in elderly men were similar to those in elderly women (for hypertension: 24.3 kg/m2 in elderly men vs 24.2 kg/m2 in elderly women; for diabetes: 24.0 kg/m2 in elderly men vs 23.7 kg/m2 in elderly women); however, BMI cut-off value for dyslipidemia was obviously higher in elderly men than that in elderly women (24.0 kg/m2 in elderly men vs 22.5 kg/m2 in elderly women). The BMI cut-off value for chronic metabolic diseases was higher in the elderly people aged 60‒74 years than that in the elderly people aged 75 years and above (24.2‒24.7 kg/m2 vs 22.9‒23.8 kg/m2).Conclusion·Elderly people aged 60‒74 years should maintain the BMI below 24.0 kg/m2, while those aged 75 years and above should aim for the BMI below 23.0 kg/m2, so as to reduce the risk of chronic metabolic diseases.

Keywords

• body mass index (bmi)
• chronic metabolic disease
• elderly