HbA1c Reduction in Diabetic Older Blacks and Hispanics: A Study on Mobile Physical Activity Tracking

Abstract

ABSTRACT Introduction/Purpose Diabetes is a leading cause of morbidity and mortality and is more prevalent in Blacks and Hispanics. This study aims to examine if different physical activity (PA) intensities reduced hemoglobin A1c (HbA1c) in Blacks and Hispanics with type 2 diabetes mellitus (DM2). Methods This pilot study used a one-sample pre- and postintervention design, including four in-person visits during a period of 3 months from January 2018 to December 2020 in Black or Hispanic populations with DM2 in the Greater Hartford, Connecticut, area. At each in-person visit HbA1c; specific, measurable, achievable, realistic, and time-bound goals; and daily PA (categorized into high-, moderate-, or low-intensity levels by a Fitbit® Charge 2) were obtained. Change scores for minutes engaged in each PA level and HbA1c values were created between visits. A linear mixed model was used to analyze these relationships over time. Results Among 17 completed participants, mean age was 56 yr, 11 were Black, 6 were Hispanic, 13 were female, and 4 were male. At baseline, mean body mass index was 34.8 kg·m−2 and mean systolic/diastolic blood pressure was 135/81 mm Hg. From 70.2 mmol·mol−1 at baseline, HbA1c decreased to 66.3 after 4 wk, 66.0 after 8 wk, and 63.5 by 12 wk (9.5% reduction, P < 0.05). Average daily PA time increased over 3 months from 15.8 to 20.3 (P = 0.04) to 20.8 (P = 0.02) minutes for moderate-intensity PA (P = 0.05), and from 12.1 to 13.6 (P = 0.08) to 15.2 (P = 0.01) minutes for high-intensity PA. PA increases were significantly associated with an overall 0.58% reduction of HbA1c (P = 0.04). Conclusion Guided by carefully selected, evidenced-based behavioral change strategies, this study found that increases of ~7 min of moderate- or high-intensity daily PA were associated with ~10% decrease in HbA1c in Blacks and Hispanics with DM2. This is consistent with the current consensus statement from the American College of Sports Medicine.