Weight loss and distal forearm fractures in postmenopausal women: the Nord-Trøndelag health study, Norway.

SUMMARY: Weight loss is a risk factor for hip fractures, but few studies have evaluated the effect of weight loss on distal forearm fracture risk. In this longitudinal study including 7,871 postmenopausal women, weight loss of 5% or more was associated with an increased risk of distal forearm fractures. INTRODUCTION: Weight loss is an established risk factor for hip fractures, but little is known about weight loss and distal forearm fractures risk. METHODS: The study included 7,871 women aged 65 years or more in the Nord-Trøndelag health study (HUNT) in 1994-1995 (HUNT II) who also had their height and weight measured in 1984-1986 (HUNT I). Forearm bone mineral density (BMD) by single energy x-ray absorptiometry was available for 5,688 women (HUNT II). Fractures sustained after HUNT II were registered during an average of 5.8 years. RESULTS: A total of 536 women sustained a distal forearm fracture. After adjustments for age and body mass index (BMI) at HUNT I, women who lost > or =5% of their weight between HUNT I and HUNT II had a relative risk of fractures of 1.33 (95% confidence interval: 1.09, 1.62) compared with the rest of the women. The higher risk of forearm fracture among women with weight loss was at least partially explained by their lower forearm BMD. CONCLUSION: Weight loss of 5% or more was associated with a 33% increased risk of distal forearm fractures.