Long-term effects of leisure time physical activity on risk of insulin resistance and impaired glucose tolerance, allowing for body weight history, in Danish men

Long-term health benefits of physical activity--a systematic review of longitudinal studies

BACKGROUND

The treatment of noncommunicable diseases (NCD), like coronary heart disease or type 2 diabetes mellitus, causes rising costs for the health system. Physical activity is supposed to reduce the risk for these diseases. Results of cross-sectional studies showed that physical activity is associated with better health, and that physical activity could prevent the development of these diseases. The purpose of this review is to summarize existing evidence for the long-term (>5 years) relationship between physical activity and weight gain, obesity, coronary heart disease, type 2 diabetes mellitus, Alzheimer's disease and dementia.

METHODS

Fifteen longitudinal studies with at least 5-year follow up times and a total of 288,724 subjects (>500 participants in each study), aged between 18 and 85 years, were identified using digital databases. Only studies published in English, about healthy adults at baseline, intentional physical activity and the listed NCDs were included.

RESULTS

The results of these studies show that physical activity appears to have a positive long-term influence on all selected diseases.

CONCLUSIONS

This review revealed a paucity of long-term studies on the relationship between physical activity and the incidence of NCD.

Interaction between physical activity and sleep duration in relation to insulin resistance among non-diabetic Chinese adults

BACKGROUND

It is of a public health interest to explore the relationship between different types of physical activity, sleep duration and diabetes/insulin resistance. However, little is known about such relationship. This study examines the single and joint associations of different types of physical activity, and sleep duration on insulin resistance among non-diabetic Chinese adults.

METHODS

Data was collected from 1124 non-diabetic adults in Jiangsu Province from the China Health and Nutrition Survey (CHNS). Domestic, occupational, transportation and leisure physical activity were assessed in terms of metabolic equivalent (MET)-hours-per-week to account for both intensity and time spent. Sleep duration was categorized into three groups: ≤ 7 hours, 7-9 hours, and ≥ 9 hours. Insulin resistance was evaluated by the homeostasis model of assessment (HOMA) and defined as the highest quartile of HOMA.

RESULTS

Total physical activity was mainly composed of occupational activity (75.1%), followed orderly by domestic, transportation and leisure time activity in both men and women. Total physical activity level was strongly negatively associated with fasting insulin and HOMA (p < 0.001). Among four types of physical activity, occupational activity was significantly negatively associated with HOMA after full adjustment (p < 0.05). Transportation activity was also negatively associated with HOMA when adjusted for age and gender (p = 0.028). Moreover, the combination of low physical activity and short sleep duration was associated with the highest odds of insulin resistance (adjusted OR = 3.26, 95% CI: 1.57-6.78), compared to those with high physical activity and adequate sleep duration.

CONCLUSIONS

Physical activity, mainly occupational physical activity, was negatively associated with insulin resistance in non-diabetic Chinese population, independently of potential confounders. There was a synergic effect of low physical activity and short sleep duration on insulin resistance.

Sweets, sweetened beverages, and risk of pancreatic cancer in a large population-based case-control study

OBJECTIVE

We examined the associations between sweets, sweetened and unsweetened beverages, and sugars and pancreatic cancer risk.

METHODS

We conducted a population-based case-control study (532 cases, 1,701 controls) and used multivariate logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI). Because associations were often different by sex, we present results for men and women combined and separately.

RESULTS

Among men, greater intakes of total and specific sweets were associated with pancreatic cancer risk (total sweets: OR = 1.9, 95% CI: 1.0, 3.6; sweet condiments: OR = 1.9, 95% CI: 1.2, 3.1; chocolate candy: OR = 2.4, 95% CI: 1.1, 5.0; other mixed candy bars: OR = 3.3, 95% CI: 1.5, 7.3 for 1 + servings/day versus none/rarely). Sweets were not consistently associated with risk among women. Sweetened beverages were not associated with increased pancreatic cancer risk. In contrast, low-calorie soft drinks were associated with increased risk among men only; while other low-/non-caloric beverages (e.g., coffee, tea, and water) were unassociated with risk. Of the three sugars assessed (lactose, fructose, and sucrose), only the milk sugar lactose was associated with pancreatic cancer risk (OR = 2.0, 95% CI: 1.5, 2.7 comparing extreme quartiles).

CONCLUSION

These results provide limited support for the hypothesis that sweets or sugars increase pancreatic cancer risk.

The metabolic syndrome, insulin resistance, and its surrogates in African and white subjects with type 2 diabetes in South Africa

BACKGROUND

Coronary heart disease (CHD) is rare in diabetic Africans in South Africa, unlike diabetic African-Americans, despite moderate levels of conventional risk factors, with absence of the usual male predominance. Because the metabolic syndrome and insulin resistance (IR) are associated with CHD, we have analyzed the prevalence and severity of the metabolic syndrome, and IR, in African and white subjects with type 2 diabetes.

METHODS

A total of 500 African and 254 white diabetic patients were evaluated for features of the metabolic syndrome (International Diabetes Federation [IDF] definition); insulin resistance (homeostasis model assessment-insulin resistance [HOMA-IR]) was calculated in subgroups.

RESULTS

In men, Africans had a lower body mass index (BMI) and smaller waists than white subjects (p < 0.0001); the metabolic syndrome was present in 46.5% and 74.1% of African and white patients respectively (p < 0.0001). In women, frequencies of the metabolic syndrome were similar, but severe metabolic syndrome (4 or 5 criteria) was more frequent in the white group (73.1%) than in the Africans (52.9%) (p = 0.0003). The prevalence of hypertriglyceridemia was lower in African men and women (p < 0.0001) and contributed to their lower prevalence of the metabolic syndrome/severe metabolic syndrome. Compared with the white patients, in African subjects HOMA-IR was 40% lower (p < 0.0001), and correlated with the triglyceride:high-density lipoprotein cholesterol ratio (TG:HDL-C) (r = 0.409, p < 0.0001).

CONCLUSIONS

In diabetic Africans, in comparison with white patients, the lower prevalence of the metabolic syndrome in men and severe metabolic syndrome in women, and lesser insulin resistance, might contribute to their lower risk of CHD; the higher prevalence in women might contribute to the reversal of the male:female ratio. The TG:HDL-C ratio appears to be a valid estimate of insulin resistance in diabetic Africans.

Type 2 diabetes but not coronary atherosclerosis is an independent determinant of impaired mobility in angiographied coronary patients

AIMS

We aimed at determining the associations of type 2 diabetes (T2DM) and of angiographically determined coronary artery disease (CAD) with impaired mobility.

METHODS

We enrolled 747 consecutive patients undergoing coronary angiography for the evaluation of stable CAD. Mobility was assessed by the standardized timed-up-and-go (TUG) test, a functional test of physical performance.

RESULTS

Mobility was impaired (TUG time >10s) in 199 (26.6%) patients. The proportion of subjects with impaired mobility was higher among patients with T2DM than among non-diabetic individuals (40.2% vs. 22.0%; p<0.001), whereas it did not differ significantly between patients with significant coronary stenoses >or=50% and those without such lesions (p=0.802). Multivariate adjustment in logistic regression analyses confirmed that T2DM (adjusted odds ratio (OR)=2.05 [95% CI 1.35-3.11]; p=0.001) but not the presence of significant coronary stenoses (adjusted OR=0.81 [0.55-1.21]; p=0.306) was independently associated with impaired mobility.

CONCLUSIONS

T2DM but not coronary atherosclerosis is an independent determinant of impaired mobility in the high risk population of angiographied coronary patients. Mobility enhancing exercise programs are needed for diabetic coronary patients.

Lack of association of fatness-related FTO gene variants with energy expenditure or physical activity

CONTEXT

A common variant in the first intron of FTO (rs9939609, T/A) is associated with fatness in Caucasians.

OBJECTIVE

FTO may regulate energy homeostasis through the hypothalamus, and we hypothesized that AA-genotypes of rs9939609 FTO have lower energy expenditure and/or a lower level of physical activity.

METHODS

The study population included all obese young men (body mass index > or = 31 kg/m(2)) at the mandatory draft board examinations in the Copenhagen area from 1943 to 1977 and a randomly selected control group from this population. Subgroups of 234 obese and 323 controls were examined in 1998-2000 (median age 48 yr). Fat mass (FM), lean body mass (LBM), leisure-time physical activity (LTPA), maximum oxygen uptake (VO(2)max), resting energy expenditure (REE), and glucose-induced thermogenesis (GIT) were measured. The FTO rs9939609 variant was genotyped. A recessive transmission mode fit the data best. Logistic regression was used to assess the odds ratios of the AA-genotype in relation to LTPA, VO(2)max, REE, and GIT.

RESULTS

The AA-genotype of FTO rs9939609 had higher REE in the age-adjusted model, but the association was eliminated when adjusting for FM and LBM. The AA-genotype was not associated with LTPA, VO(2)max, or GIT. This was not influenced by adjustment for age, FM, or LBM. The AA-genotype had increased FM, even with adjustment for age, LBM, REE, GIT, VO(2)max, and LTPA. Results were similar for FTO rs8050136 and rs7193144.

CONCLUSIONS

Homozygous carriers of the A-allele of rs9939609 FTO do not have lower REE, GIT, VO(2)max, or LTPA but higher FM, irrespective of LBM, REE, GIT, VO(2)max, and LTPA.