Increasing overall physical activity and aerobic fitness is associated with improvements in metabolic risk: cohort analysis of the ProActive trial

Abstract

Our aim was to examine the association between change in physical activity energy expenditure (PAEE), total body movement (counts per day) and aerobic fitness (maximum oxygen consumption [\({\mathop {\text{V}}\limits^{\text{.}} }{\text{O}}_{{2\max }} \)]) over 1 year and metabolic risk among individuals with a family history of diabetes. Three hundred and sixty-five offspring of people with type 2 diabetes underwent measurement of energy expenditure (PAEE measured using the flex heart rate method), total body movement (daily activity counts from accelerometry data), \({\mathop {\text{V}}\limits^{\text{.}} }{\text{O}}_{{2\max }} \) predicted from a submaximal graded treadmill exercise test and anthropometric and metabolic status at baseline and 1 year (n = 321) in the ProActive trial. Clustered metabolic risk was calculated by summing standardised values for waist circumference, fasting triacylglycerol, insulin and glucose, blood pressure and the inverse of HDL-cholesterol. Linear regression was used to quantify the association between changes in PAEE, total body movement and fitness and clustered metabolic risk at follow-up. Participants increased their activity by 0.01 units PAEE kJ kg−1 day−1 over 1 year. Total body movement increased by an average of 9,848 counts per day. Change in total body movement (β = −0.066, p = 0.004) and fitness (β = −0.056, p = 0.003) was associated with clustered metabolic risk at follow-up, independently of age, sex, smoking status, socioeconomic status and baseline metabolic score. Small increases in activity and fitness were associated with a reduction in clustered metabolic risk in this cohort of carefully characterised at-risk individuals. Further research to quantify the reduction in risk of type 2 diabetes associated with feasible changes in these variables should inform preventive interventions. Clinical trial registration number: ISRCTN61323766.