Leisure-time, occupational, household physical activity and insulin resistance (HOMAIR) in the Midlife in the United States (MIDUS) national study of adults

Physical activity is a critical cornerstone of successful diabetes prevention and management. Current U.S. physical activity guidelines do not differentiate among physical activity for leisure, work, or other purposes, effectively implying that physical activity in any domain confers the same health benefits. It is currently unknown whether physical activity performed in different domains (leisure-time physical activity = LTPA, occupational physical activity = OPA, and household physical activity = HPA) is associated with insulin resistance. The associations between LTPA, OPA, HPA, and insulin resistance (indexed by homeostatic model assessment of insulin resistance = HOMAIR) were determined in the MIDUS (Midlife in the U.S.; 1995-2006) national study (N = 1229, ages 34-84). Not meeting physical activity guidelines with LTPA was associated with a 34% higher HOMAIR among participants with diabetes, 42% higher HOMAIR among participants with prediabetes, and 17% higher HOMAIR among participants with normal glucoregulation. These associations were slightly attenuated but remained significant after further adjusting for obesity status, education, smoking, and alcohol intake. There was no evidence that engaging in OPA or HPA was significantly associated with HOMAIR. These results confirm the health-promoting role of LTPA and suggest that LTPA may provide unique glucoregulatory benefits, as opposed to HPA and OPA. Physical activity domain is an important dimension that potentially belongs in the guidelines, similarly to intensity, frequency, duration, and type.