Associations of General Adiposity, Abdominal Adiposity, and Their Changes With Fracture Risk in Chinese Individuals With Type 2 Diabetes: A Population-Based Cohort Study in Hong Kong

OBJECTIVE: To investigate the associations of baseline general and abdominal adiposity, as well as their longitudinal changes, with risks of any-site, major osteoporotic, and site-specific fractures in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: Individuals with type 2 diabetes who underwent structured assessments in the Hong Kong Hospital Authority between August 2001 and February 2022 were followed for incident fractures until June 2024. Multivariable Cox regression and restricted cubic spline analyses were used to evaluate the associations of baseline BMI, waist circumference, and their 2-year percentage changes with fracture risk. RESULTS: Among 436,929 individuals (mean ± SD age 61.9 ± 11.8 years, median [interquartile range] diabetes duration 1 [0-6] years, 53.1% men) followed for a median of 8.3 years, underweight was associated with 30-77% higher risks of any-site, major osteoporotic, hip, and pelvis fractures, whereas class II obesity was associated with 21-36% higher risks of humerus, upper leg, and ankle fractures. Waist circumference residuals from BMI were positively associated with fracture risk. Among 247,540 individuals with 2-year adiposity measurements, weight change showed U-shaped associations with any-site, major osteoporotic, hip, and humerus fractures, with the lowest risks at -1.5% to 2.3% weight change. Increases in waist circumference were positively associated with risks of any-site, major osteoporotic, hip, rib, humerus, and elbow fractures. CONCLUSIONS: In individuals with type 2 diabetes, general adiposity showed site-specific associations with fracture risk, with its longitudinal changes demonstrating U-shaped relationships, whereas abdominal adiposity and its increases were independently associated with higher fracture risk.