Modifiable Factors Associated with Bone in Premenopausal Women with Type 1 Diabetes

Modifiable Factors Associated with Bone in Premenopausal Women with Type 1 Diabetes Bone fragility has been identi Bone fragility has been identified as a complication of type 1 diabetes (T1D). The reasons for skeletal compromise have yet to be determined. This study is a secondary data analysis of premenopausal women with T1D (n=89) who were part of the Wisconsin Diabetes Registry and matched controls (n=76). Peripheral (heel, wrist) and central (hip, spine) bone mineral density (BMD; g/cm[sup]2[/sup]), measures of bone formation (Osteocalcin and Bone-Specific Alkaline Phosphatase) and resorption (N-terminal cross-linked telopeptide and Tartrate-Resistant Acid Phosphatase Isoform 5b), and dietary and lifestyle factors were analyzed. Multivariable stepwise regression modeling was used to identify significant associations with BMD and bone turnover markers stratified by diabetes status; effect modification by diabetes status was also tested in the entire sample. BMI and vigorous physical activity were positively associated with central BMD in controls (p[le]0.03) but not in women with T1D. Similarly, waist-to-hip ratio was positively associated with wrist BMD in controls (p=0.03) but not in women with T1D (interaction p=0.02). Use of estrogen contraception (former [beta]=-0.02 and current [beta]=-0.04) and higher A1C (%; [beta]=-0.01) were detrimental to peripheral BMD in women with T1D (p[le]0.03). Sun exposure was associated with higher hip BMD in women with T1D (p=0.01) but not in controls (interaction p=0.03). With regard to bone turnover, age was negatively associated with all four markers in controls (p[le]0.04) but not women with T1D. Greater alcohol and caffeine consumption, and smoking were associated with altered bone resorption in women with T1D (p[le]0.03;smoking interaction p=0.04). In conclusion, age, BMI and vigorous physical activity, traditional clinical predictors of bone fragility, may not be associated with bone in women with T1D. Estrogen contraception use, poor glycemic control, caffeine, alcohol, and smoking may negatively impact bone in women with T1D whereas sun exposure may have a positive effect on bone health. Modifiable behaviors play a large role in the bone health of women with T1D and offer several opportunities for education and intervention to improve bone in this population. AMBER S. KUJATH, KIRSTIE K. DANIELSON, LAURETTA QUINN, MARI PALTA 1283-P Chicago, IL, Madison, WI Epidemiology