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Abstract
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BACKGROUND: The impact of walking and bicycling on insulin resistance (IR) in women with abdominal obesity is unclear.
METHODS: Pooled analysis of data from a randomized trial on physically active commuting (bicycling + walking vs walking only) in women with abdominal obesity [n = 98; age:47.3 +/- 7.6 yrs; waist circumference (WC):103.1 +/- 7.8 cm]. Bicycling and walking data were collected during 7 consecutive days by trip meters (Trelock FC-410) and pedometers (Yamax digiwalker SW-200) at baseline, 2, 4, and 6 months. Owing to a skew distribution we analyzed bicycling as a binary dummy variable with a 10 km/week cut-off. Fasting serum insulin and homeostatic model assessment - insulin resistance (HOMA-IR) were assessed at baseline and 6 months, as were body mass index (BMI), WC, and dual x-ray absorptiometry (DXA)-assessed % whole-body fat.
RESULTS: Increased bicycling by 10 km/wk was associated with reductions in fasting serum insulin at follow-up independent of age, treatment allocation, baseline phenotype, Delta walking, and Delta % body fat (beta = -10.9, P =.042), but not HOMA-IR (beta = -2.0, P =.13). Increased walking was not associated with fasting serum insulin (P =.33) or HOMA-1R (P =.44) at follow-up, after adjustment for the same covariates and Delta bicycling.
CONCLUSION: Increased bicycling but not walking was associated with reduced insulin levels at follow-up. Bicycling may be more effective than walking for reducing insulin levels in abdominally obese women.
Language: en |