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.
Swartz
Ann M
AM
Department of Human Movement Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisc., USA. aswartz@uwm.edu
Strath
Scott J
SJ
Miller
Nora E
NE
Cashin
Susan E
SE
Cieslik
Linda J
LJ
D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D005215:Fasting; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D044469:Racial Groups; D012044:Regression Analysis; D049629:Waist-Hip Ratio; D016138:Walking
D001786:Blood Glucose; D006442:Glycated Hemoglobin