**3.1.3 Physical activity**

One cross-sectional study (Kriska AM et al. 1991) examined the relationship between physical activity and the occurrence of retinopathy in type 1 diabetic patients. They found no association between physical activity (sports and leisure physical activity) and occurrence of retinopathy.

Diet, Lifestyle and Chronic Complications in Type 1 Diabetic Patients 29

events approximating CVD risk. The opposite was true for carbohydrate intake, higher

In conclusion a higher intake of total fat as well as saturated fat is positively correlated with CVD or CVD risk factors (atherosclerosis and CAC in these studies) and a higher intake of carbohydrate is negatively correlated with CVD or CVD risk factors. Furthermore dietary fiber is independently related to a lower risk for CVD in type 1 diabetic women. Since all these studies were cross-sectional, they could only look at the intake of certain nutrients and the prevalence of CVD or CVD risk factors at a certain time point. They could not conclude if these are related to each other and if the nutrients are responsible for the lower or higher

Two randomized controlled trials reported an association between macronutrients and CVD (**Table 2**), but demonstrated conflicting conclusions. In one trial (Strychar I et al. 2009), the authors concluded that a diet lower in carbohydrate and higher in MUFA might be preferable to a diet higher in carbohydrate and lower in MUFA for type 1 diabetic patients. This was solely based on the positive effect on triglyceride (TG) levels and plasminogen activator inhibitor 1 levels (PAI-1) in the first diet. A significant decrease in PAI-1 was found after 6 months in the lower carbohydrate and higher MUFA diet. In the other diet there was a significant increase after 6 months of follow up. PAI-1 is an inhibitor of fibrinolysis, a process that degrades blood clots. A lower level of PAI-1 means less inhibition and more degradation of blood clots, which means a lower chance of developing atherosclerosis. Also a decrease in TG levels was found after 6 months following the low carbohydrate/high MUFA diet, although this decrease was not significant. In the other diet group there was an increase in TG levels, also this increase was not significant. Furthermore they conclude that the lower carbohydrate/higher MUFA diet was only a proper choice for nonobese individuals with weight control since this diet had induced a weight gain of 2% (1.6 kg) after 6 months. The other trial (Georgopoulos A et al. 2000) found exactly the opposite using a crossover design. They found that a diet high in carbohydrates might be preferable to a diet high in MUFA. Mainly because of the higher atherosclerotic risk due to more and bigger very low-density lipoprotein (VLDL) particles in the last diet. Furthermore the TG levels did

In conclusion, these trials show that the effect of carbohydrate or MUFA on cardiovascular disease risk factors in type 1 diabetic patients is still not elucidated. Although they recommend exactly the opposite (higher intake of MUFA preferable vs. higher intake of carbohydrate preferable) they both found that a high MUFA or a high carbohydrate diet did not affect the TG levels. Their conclusions are based on PAI-1 and VLDL levels, which are not such a good predictors for atherosclerosis (and by extension CVD) as TG levels are. Furthermore none of these randomized controlled trials examined the potential positive effect of dietary fiber on CVD or the potential negative effect of saturated fat found in cross-

One cross-sectional study (Bishop et al. 2009) reported findings on the association between alcohol and cardiovascular disease. No significant association was found between alcohol consumption (±13.8 drinks/month) and CAC, a marker of coronary artery atherosclerosis (adjusted OR=0.9, 95% CI: 0.8-1.1, p=0.15). The positive effect of moderate alcohol

intake was associated with a reduced odds of CAC.

not significantly differ between the two diets in this study.

prevalence of CVD.

sectional studies.

**4.4 Alcohol** 

**4.3 Randomized controlled trials** 
