Inactive adults face higher heart disease risk
People who spend a lot of time sitting down do not reduce the risk of getting type 2 diabetes and heart disease by doing exercise, new research has found.
Physical activity needs to be sustained throughout the week to have a real effect on lifespan and counter the diabetes risk. Research by the MRC Epidemiology Unit will appear in Diabetes this week.
Results suggest the detrimental effect of sedentary living on insulin resistance was not dependent of adiposity (how overweight a person is), smoking and the amount of time being physically active. Therefore, it is important to not only recommend people be more physically active but also that they reduce the amount of time they spend sitting.
Dr Ulf Ekelund led a team of researchers in studying 376 middle-aged adults over more than five years for the study.
Each person’s heart rate was measured every minute while they were awake, then used to define a specific heart rate for each individual which corresponded to when that person was inactive. Scientists then calculated the number of minutes each person (166 men, 210 women) spent below their threshold.
This information was analysed to see if there was an association between time spent sedentary over four days and fasting plasma insulin levels, a measure of insulin resistance.
Dr Ekelund said:
“This is the first study demonstrating that sedentary living is associated with an adverse metabolic profile 5 to 6 years later, suggesting a causal association between physical inactivity and insulin resistance. Furthermore, this relationship was independent of age, sex, adiposity and time spent physically active.
“The results may provide further evidence for the need of public health guidelines on decreasing sedentary behaviour, in addition to the established guidelines for physical activity in adults.
“Most people in modern society spend the majority of their awake time sedentary. We were interested to examine whether time spent sedentary could predict insulin resistance, a precursor for the metabolic syndrome and type 2 diabetes.”
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