Glucose control and walking in a multiethnic sample of older adults.

Background: Although walking is the most commonly reported physical activity by older adults, there is a paucity of data determining the relationship between objectively determined walking behavior and glucose dynamics in older adults.

Objective: This study was designed to investigate the relationship between objectively determined walking behavior and glucose control in a multiethnic sample of older adults.

Methods: Data were collected on 142 older adults (age 72.1 +/- 9.2 years; body mass index (BMI) 29.4 +/- 6.3; 37 males, 105 females). Anthropometric measures, fasting plasma glucose (FG), and glycosylated hemoglobin A(1c) (HbA(1c)) were assessed; race/ethnicity was self-reported. The study participants wore a pedometer for 7 consecutive days.

Results: The average number of steps/day reported by the entire group was 3,939 +/- 232. White participants (n = 48) were older (p = 0.019), taller (p = 0.002), had lower waist circumference (WC) (p = 0.021), HbA(1c) (p = 0.001) and FG (p = 0.007), and did not differ in average steps/day (p = 0.162) or BMI (p = 0.280) as compared with nonwhite participants (n = 94). Individuals with HbA(1c) values <7% and those with FG <100 mg/dl walked about 1,343 more steps/day than those with unfavorable HbA(1c) and/or FG values. Age, race/ethnicity, WC, BMI, log base 10 of steps/days, and type 1 and 2 diabetes medications accounted for 37.5% of the variance in inverse HbA(1c) (p < 0.001), with significant or near significant individual model contributions consisting of WC (beta = -0.316, B = -0.001, SE = 0.000, p = 0.047), BMI (beta = 0.310, B = 0.001, SE = 0.001, p = 0.050), diabetic medication (beta = -0.473, B = -0.035, SE = 0.006, p < 0.001), and log base 10 of steps/day (beta = 0.198, B = 0.019, SE = 0.010, p = 0.056). Interpretations of transformed data illustrate that greater WC and being on diabetic medications are associated with higher HbA(1c) levels. Further, there is a trend to suggest that fewer accumulated steps/day and lower BMI are associated with higher HbA(1c) concentrations.

Conclusions: This study demonstrated that objectively determined walking behavior and indicators of obesity were modest predictors of chronic glucose control, after accounting for glucose-altering medications, in this multicultural sample of older adults. Further, when comparing individuals with good glucose control to those with less favorable glucose control, walking an additional 0.5-0.75 miles was associated with better glucose control.