Risk factors for fractures among Japanese-American men: The Honolulu Heart Program and Honolulu-Asia Aging Study

Abstract

Baseline risk factors were associated with fractures that developed after 29-31 years among Japanese-American men. Hip fracture risk increased with increasing BMI (28% increase for 1 U increase), physical activity (7% increase for 1 U increase), and was decreased with increasing arm girth (27% decrease for 1 U increase).

Purpose: The objective of this study was to identify risk factors among Japanese-American men aged 45-68 years at baseline that were associated with prevalence and incidence of fractures at advanced age.

Methods: We used baseline information from Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS). The HHP was a prospective study with primary focus on risk factors for cardiovascular disease. A cohort of 8,006 men of Japanese ancestry aged 45-68 years residing on Oahu was recruited in 1965 and followed for 31 years. The HAAS started in 1991 in conjunction with the HHP with a focus on age-related health conditions. Self-reported hip, spine, and forearm fracture prevalence was ascertained in 1991-1993 among 3,845 men aged 71-93 years. Incidence was obtained during the period (1994-1999) among 2,737 men aged 74-98 years. Poisson regression models were used to determine multi-variable adjusted prevalence and incidence ratios for fracture.

Results: Incident hip fracture was directly associated with baseline body mass index (BMI) and physical activity, and inversely associated with left upper arm girth. Incident spine fracture was directly associated with baseline age. Prevalent hip fracture was directly associated with baseline pack-years of smoking. Prevalent spine fracture was inversely associated with baseline education, and directly associated with standing height and use of medication for diabetes. Prevalent forearm fracture was inversely associated with baseline age, and directly associated with education.

Conclusions: Results indicated that multiple baseline demographic lifestyle and anthropometric characteristics predict fracture risk at advanced age. In addition, associations varied by fracture location.