Format

Send to:

Choose Destination
See comment in PubMed Commons below
Diabetes. 2009 Aug;58(8):1776-9. doi: 10.2337/db08-1773. Epub 2009 May 26.

Objectively measured sedentary time may predict insulin resistance independent of moderate- and vigorous-intensity physical activity.

Author information

  • 1Medical Research Council Epidemiology Unit, Cambridge, UK.

Abstract

OBJECTIVE:

To examine the prospective association between objectively measured time spent sedentary and insulin resistance and whether this association is independent of moderate- and vigorous-intensity physical activity (MVPA) and other relevant confounders.

RESEARCH DESIGN AND METHODS:

This was a population-based study (Medical Research Council Ely study) in 376 middle-aged adults (166 men; 210 women) over 5.6 years of follow-up. Physical activity and sedentary time were measured objectively by individually calibrated minute-by-minute heart rate monitoring at both baseline and follow-up. Sedentary time was calculated as the heart rate observations (in minutes) below an individually predetermined threshold (flex heart rate) and expressed as a percentage of total monitored time during waking hours over 4 days. The percentage of time spent above 1.75 x resting heart rate represented MVPA. Fasting plasma insulin was used as a surrogate measure of insulin resistance.

RESULTS:

Time spent sedentary at baseline was significantly and positively associated with log fasting insulin at follow-up (beta = 0.003, 95% CI 0.0006-0.006, P = 0.015) independent of baseline age, sex, fat mass, fasting insulin, smoking status, and follow-up time. After further adjustment for MVPA, this association was somewhat strengthened (beta = 0.004, 95% CI 0.0009-0.006, P = 0.009).

CONCLUSIONS:

Time spent sedentary predicts higher levels of fasting insulin independent of the amount of time spent at moderate- and vigorous-intensity activity levels. This highlights the importance of reducing sedentary time in order to improve metabolic health, possibly in addition to the benefits associated with a physically active lifestyle.

PMID:
19470610
[PubMed - indexed for MEDLINE]
PMCID:
PMC2712788
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk