In the Journals

Physical activity, sedentary behavior associated with type 2 diabetes risk

Vigorous physical activity, exercise and a brisk walking pace can lower the risk for incident type 2 diabetes in adults; whereas increased sedentary behavior and television watching time can increase the risk, according to recent study findings.

Joshua J. Joseph, MD, clinical and research fellow at Johns Hopkins University School of Medicine in Baltimore, and colleagues analyzed data from 5,829 adults participating in the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of four racial groups without diagnosed cardiovascular disease or diabetes at baseline (mean age, 62 years; 54% women; 42% white; 12% Chinese; 26% black; 21% Hispanic). Participants completed a Typical Week Physical Activity Survey to assess baseline moderate, vigorous and exercise-specific physical activity, and metabolic equivalents of task-hours per week and sedentary behaviors (television watching, reading; hours/day). Incident diabetes was assessed in five in-person examinations between 2002 and 2012. Researchers used Cox proportional hazard models to estimate HRs.

Over a median follow-up of 11.1 years, there were 655 incident diabetes cases (11.4 per 1,000 person-years), with a higher incidence rate among blacks and Hispanics. Participants who reported some vigorous activity (n = 1,914) vs. none (n = 3,915) were less likely to develop type 2 diabetes (9.5% vs. 12.4%; P < .05) as were those who had a walking pace of 4 vs. 2 MPH (9% vs. 15.3%; P < .001).

After multivariable adjustment, diabetes risk was lower in those with brisk or striding walking pace vs. none or casual walking pace (HR = 0.67; 95% CI, 0.54-0.84).

Diabetes risk was also lower in adults who reported a higher levels of physical activity vs. those in the lowest quartile (HR = 0.79; 95% CI 0.63 to 0.98), as well as those who reported and any vigorous physical activity vs. none (HR = 0.79; 95% CI, 0.66-0.95).

Researchers found that race influenced the association of walking pace, exercise physical activity, and any vigorous physical activity on diabetes risk, which was only significant among whites.

Participants who reported higher levels of total leisure sedentary behaviors (at least 6 hours daily) also had a higher risk for type 2 diabetes vs. those who reported 2 hours per day or less of leisure behavior (HR = 1.65; 95% CI, 1.26-2.14). In addition, participants who reported watching television for at least 6 hours daily had the greatest risk for incident type 2 diabetes vs. those who reported watching 2 hours per day or less (HR = 2.68; 95% CI, 1.38-5.21); race influenced the association for leisure behaviors.

“The independent protective associations of vigorous [physical activity] and activity score, along with the deleterious associations of leisure sedentary behavior on type 2 diabetes risk remained after full adjustment, including BMI,” the researchers wrote.

The magnitude of the associations varied by race/ethnicity, the researchers noted, with the statistical significance of the associations in the overall cohort driven by the white subgroup, as the black, Hispanic and Chinese groups achieved only a P < .05 among blacks for television watching and among Hispanic adults for activity score.

“The duality of these findings, combined with the greater burden of type 2 diabetes in racial/ethnic minority populations, suggests other factors that vary by race/ethnicity may play important roles in the development of type 2 diabetes in [non-white] populations, including diet, social determinants of health, chronic stress/allostatic load, sleep insufficiency and inflammation,” the researchers wrote. “While our findings of potential racial/ethnic differences in the association of activity measures with type 2 diabetes incidence should be considered with some caution due to sample size variation in race/ethnic groups, there are some plausible biological mechanisms that may explain these findings.”

The researchers noted that further investigation into complementary risk reduction strategies may be especially relevant for ethnic minorities and those with a family history of diabetes. – by Regina Schaffer

Disclosure: The researchers report no relevant financial disclosures.

Vigorous physical activity, exercise and a brisk walking pace can lower the risk for incident type 2 diabetes in adults; whereas increased sedentary behavior and television watching time can increase the risk, according to recent study findings.

Joshua J. Joseph, MD, clinical and research fellow at Johns Hopkins University School of Medicine in Baltimore, and colleagues analyzed data from 5,829 adults participating in the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of four racial groups without diagnosed cardiovascular disease or diabetes at baseline (mean age, 62 years; 54% women; 42% white; 12% Chinese; 26% black; 21% Hispanic). Participants completed a Typical Week Physical Activity Survey to assess baseline moderate, vigorous and exercise-specific physical activity, and metabolic equivalents of task-hours per week and sedentary behaviors (television watching, reading; hours/day). Incident diabetes was assessed in five in-person examinations between 2002 and 2012. Researchers used Cox proportional hazard models to estimate HRs.

Over a median follow-up of 11.1 years, there were 655 incident diabetes cases (11.4 per 1,000 person-years), with a higher incidence rate among blacks and Hispanics. Participants who reported some vigorous activity (n = 1,914) vs. none (n = 3,915) were less likely to develop type 2 diabetes (9.5% vs. 12.4%; P < .05) as were those who had a walking pace of 4 vs. 2 MPH (9% vs. 15.3%; P < .001).

After multivariable adjustment, diabetes risk was lower in those with brisk or striding walking pace vs. none or casual walking pace (HR = 0.67; 95% CI, 0.54-0.84).

Diabetes risk was also lower in adults who reported a higher levels of physical activity vs. those in the lowest quartile (HR = 0.79; 95% CI 0.63 to 0.98), as well as those who reported and any vigorous physical activity vs. none (HR = 0.79; 95% CI, 0.66-0.95).

Researchers found that race influenced the association of walking pace, exercise physical activity, and any vigorous physical activity on diabetes risk, which was only significant among whites.

Participants who reported higher levels of total leisure sedentary behaviors (at least 6 hours daily) also had a higher risk for type 2 diabetes vs. those who reported 2 hours per day or less of leisure behavior (HR = 1.65; 95% CI, 1.26-2.14). In addition, participants who reported watching television for at least 6 hours daily had the greatest risk for incident type 2 diabetes vs. those who reported watching 2 hours per day or less (HR = 2.68; 95% CI, 1.38-5.21); race influenced the association for leisure behaviors.

“The independent protective associations of vigorous [physical activity] and activity score, along with the deleterious associations of leisure sedentary behavior on type 2 diabetes risk remained after full adjustment, including BMI,” the researchers wrote.

The magnitude of the associations varied by race/ethnicity, the researchers noted, with the statistical significance of the associations in the overall cohort driven by the white subgroup, as the black, Hispanic and Chinese groups achieved only a P < .05 among blacks for television watching and among Hispanic adults for activity score.

“The duality of these findings, combined with the greater burden of type 2 diabetes in racial/ethnic minority populations, suggests other factors that vary by race/ethnicity may play important roles in the development of type 2 diabetes in [non-white] populations, including diet, social determinants of health, chronic stress/allostatic load, sleep insufficiency and inflammation,” the researchers wrote. “While our findings of potential racial/ethnic differences in the association of activity measures with type 2 diabetes incidence should be considered with some caution due to sample size variation in race/ethnic groups, there are some plausible biological mechanisms that may explain these findings.”

The researchers noted that further investigation into complementary risk reduction strategies may be especially relevant for ethnic minorities and those with a family history of diabetes. – by Regina Schaffer

Disclosure: The researchers report no relevant financial disclosures.