Study on Lifestyle Intervention and Impaired Glucose Tolerance Maastricht (SLIM): preliminary results after one year

AIMS

Important risk factors for the progression from impaired glucose tolerance to type II diabetes mellitus are obesity, diet and physical inactivity. The aim of this study is to evaluate the effect of a lifestyle-intervention programme on glucose tolerance in Dutch subjects with impaired glucose tolerance (IGT).

METHODS

A total of 102 subjects were studied, randomised into two groups. Subjects in the intervention group received regular dietary advice, and were stimulated to lose weight and to increase their physical activity. The control group received only brief information about the beneficial effects of a healthy diet and increased physical activity. Before and after the first year, glucose tolerance was measured and several other measurements were done.

RESULTS

Body weight loss after 1 y was higher in the intervention group. The 2-h blood glucose concentration decreased 0.8+/-0.3 mmol/l in the intervention group and increased 0.2+/-0.3 mmol/l in the control group (P<0.05). Body weight loss and increased physical fitness were the most important determinants of improved glucose tolerance and insulin sensitivity.

CONCLUSION

A lifestyle-intervention programme according to general recommendations is effective and induces beneficial changes in lifestyle, which improve glucose tolerance in subjects with IGT. Body weight loss and increased physical fitness were the most important determinants of improved glucose tolerance and insulin sensitivity.

Long-term effect of fish oil diet on basal and stimulated plasma glucose and insulin levels in ob/ob mice

In this study, the ob/ob mouse model was used to investigate epidemiological evidence linking fish intake to relative reduction in incidence of Type 2 diabetes mellitus and glucose. We have investigated, in comparison to low and high fat diets, the effect of a fish oil diet on basal and stimulated plasma glucose and insulin levels in male and female ob/ob mice. Mice were fed for 12 months with a saturated fat diet containing 25% lard, with a low fat diet containing 5% soybean oil, with a polyunsaturated fat diet containing 25% safflower seed oil (n-6) or with polyunsaturated fat diet containing 23% fish oil (n-3). Total body weight increased to approximately 100 g at the end of the experiment, with the highest increase in the order of lard > safflower oil > fish oil > soybean oil diet. Intercurrent deaths were found especially in the fish oil diet group. Compared to the other diet groups, plasma insulin levels of the fish oil diet group were significantly increased 3 months after the start of the diet and remained higher for another 3 months. Thereafter, the level declined to those of the other diet groups. Glucose-tolerance tests at 3, 6, 8 and 10 months showed a tendency of more efficient tissue glucose uptake in the fish oil group compared to the other groups, which was in accordance with a higher plasma insulin levels. At 12 months, microscopy revealed an increased severity of hepatic brown pigment accumulation and extramedullary haematopoiesis in the spleen of mice fed with fish oil. We conclude that fish oil diet in ob/ob mice reduced the body weight gain and increased the glucose-induced insulin secretion. Fish oil diet also increased intercurrent mortality. However, a consistent course of death could not be established using morphological parameters.

Diet and 20-year chronic obstructive pulmonary disease mortality in middle-aged men from three European countries

OBJECTIVE

To investigate the relation of baseline antioxidant, fruit, vegetable and fish intake with 20 y chronic obstructive pulmonary disease (COPD) mortality in middle-aged men from three European countries.

DESIGN

Prospective study (1970-1990).

SETTING

Five population-based cohorts of middle-aged men from Finland, Italy and The Netherlands.

SUBJECTS

A total of 2917 men aged 50-69 y at baseline.

METHODS

Baseline information on diet was collected using the cross-check dietary history method. After 20 y of follow-up the underlying cause of death of those who died was established centrally. Survival analyses were performed using the Cox Proportional Hazards Model.

RESULTS

After adjustment for age, smoking and country, we observed an inverse trend (P-trend <0.05) of 20 y COPD mortality across tertiles of fruit and vitamin E intake. No trend was observed for vegetables, fish, vitamin C and beta-carotene. When modelled continuously, a 100 g increase in fruit intake was associated with a 24% lower COPD mortality risk (RR=0.76, 95% CI=0.60-0.92). For vitamin E intake (per 5 mg) the RR was 0.77 (95% CI=0.55-1.06), after adjustment for age, smoking and country. Additional adjustment for body mass index, total energy intake and alcohol consumption reduced the RR to 0.86 (95% CI=0.69-1.07, P=0.12) for fruit and 0.93 (95% CI=0.65-1.33) for vitamin E.

CONCLUSIONS

Our results suggest a protective effect of fruit and possibly vitamin E intake against COPD. No effect was observed for intake of vitamin C, beta-carotene, vegetables and fish.