Aims/hypothesis
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 [
\textV\text. \textO2max {\mathop {\text{V}}\limits^{\text{.}} }{\text{O}}_{{2\max }} ]) over 1 year and metabolic risk among individuals with a family history of diabetes.
Methods
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),
\textV\text. \textO2max {\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.
Results
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.
Conclusions/interpretation
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.
Keywords Cardio-respiratory fitness - Fitness - Metabolic risk - Metabolic syndrome - Physical activity - Syndrome X
The other members of the ProActive research team, besides the authors, are listed in Acknowledgements.