HABITUAL PHYSICAL-ACTIVITY, AEROBIC CAPACITY AND METABOLIC CONTROL INPATIENTS WITH NEWLY-DIAGNOSED TYPE-2 (NON-INSULIN-DEPENDENT) DIABETES-MELLITUS - EFFECT OF 1-YEAR DIET AND EXERCISE INTERVENTION

The aim of this study was to asses the effects of a 1-year intensified diet and exercise education regimen on habitual physical activity and aerobic capacity in middle-aged, obese patients with newly-diagnosed Type 2 (non-insulin-dependent) diabetes mellitus. In addition, we anal ysed whether the level and the changes in physical activity and aerobi c capacity are related to the metabolic control of diabetes. After a 3 -month basic education programme, 78 patients (45 men, 33 women) were randomly placed in an intervention or conventionally treated group. Th e intervention group received intensified diet education and continuou s encouragement to increase physical activity which was monitored usin g exercise records and questionnaires. Aerobic capacity was assessed b y measuring oxygen uptake at anaerobic threshold and at peak exercise. The proportion of patients with regular recreational exercise increas ed from 24% to 38% in the intervention men (0.10 < p < 0.20), remained at 54% in the conventionally treated men, increased from 53% to 70% i n the intervention women (0.10 < p < 0.20) and from 31% to 50% (0.10 < p < 0.20) in the conventionally treated women. No measurable improvem ent was found in oxygen uptake in any of the groups. When the groups w ere combined, HbA1c showed an inverse correlation with oxygen uptake a t an-aerobic threshold (r = - 0.27, p < 0.01) and maximum oxygen uptak e (r = - 0.28, p < 0.01) at 12 months. The change in maximum oxygen up take was linearly correlated with the change in HDL-cholesterol (r = 0 .28,p < 0.01) and those patients with improved aerobic capacity (n = 3 7) had higher HDL-cholesterol level at the end of the study than those (n = 41) with unaltered or decreased aerobic capacity (1.27 +/- 0.27 vs 1.12 +/- 0.25 mmol.l-1, mean +/- SD;p < 0.05). In conclusion, in th is long-term prospective study repeated encouragement and follow-up us ing exercise records was not sufficient to induce a significant increa se in physical activity and an improvement in aerobic capacity in diab etic patients. Our results suggest, however, that high aerobic capacit y is beneficial for glycaemic control, and on the other hand, even sli ght increase in aerobic capacity is associated with an increase in HDL -cholesterol level.