Minimal intensity physical activity (standing and walking) of longer duration improves insulin action and plasma lipids more than shorter periods of moderate to vigorous exercise (cycling) in sedentary subjects when energy expenditure is comparable.

Epidemiological studies suggest that excessive sitting time is associated with increased health risk, independent of the performance of exercise. We hypothesized that a daily bout of exercise cannot compensate the negative effects of inactivity during the rest of the day on insulin sensitivity and plasma lipids.Eighteen healthy subjects, age 21±2 year, BMI 22.6±2.6 kgm(-2) followed randomly three physical activity regimes for four days. Participants were instructed to sit 14 hr/day (sitting regime); to sit 13 hr/day and to substitute 1 hr of sitting with vigorous exercise 1 hr (exercise regime); to substitute 6 hrs sitting with 4 hr walking and 2 hr standing (minimal intensity physical activity (PA) regime). The sitting and exercise regime had comparable numbers of sitting hours; compared to the exercise regime, the minimal intensity PA regime had a higher estimated daily energy expenditure (238kcal/day) [corrected]. PA was assessed continuously by an activity monitor (ActivPAL) and a diary. Measurements of insulin sensitivity (oral glucose tolerance test, OGTT) and plasma lipids were performed in the fasting state, the morning after the 4 days of each regime. In the sitting regime, daily energy expenditure was about 500 kcal lower than in both other regimes. Area under the curve for insulin during OGTT was significantly lower after the minimal intensity PA regime compared to both sitting and exercise regimes 6727.3±4329.4 vs 7752.0±3014.4 and 8320.4±5383.7 mU•min/ml, respectively. Triglycerides, non-HDL cholesterol and apolipoprotein B plasma levels improved significantly in the minimal intensity PA regime compared to sitting and showed non-significant trends for improvement compared to exercise.One hour of daily physical exercise cannot compensate the negative effects of inactivity on insulin level and plasma lipids if the rest of the day is spent sitting. Reducing inactivity by increasing the time spent walking/standing is more effective than one hour of physical exercise, when energy expenditure is kept constant

Bone turnover and hip bone mineral density in patients with sarcoidosis

Background and aim of the work: Sarcoidosis is a chronic inflammatory T-cell-driven disease can also affect bone. We evaluated bone remodelling and bone mineral density (BMD) in patients with coidosis and their dependency of disease-related and treatment-related factors. Methods: In 124 BMD of the hip (DXA) and markers of bone resorption (ICTP) and formation (PINP) were evaluated. thermore a lateral DXA of the spine for morphometric assessment of vertebral deformities was performed 87 patients. Potential predictors of bone markers, BMD and determinants of prevalent vertebral were assessed using multiple and logistic regression analysis. Results: The population studied comprised treated patients (n = 51), patients that previously used glucocorticoids (n = 31) and patients currently glucocorticoids (n = 42). In all these groups the age- and gender corrected Z-scores of the hip were except in untreated patients, which revealed an increased Z-score at the trochanter (p = 0.004). In all but patients currently on glucocorticoids the Z-scores for PINP and ICTP were increased (p <0.05). In currently on glucocorticoids the Z-ICTP was also increased (p <0.05), but the Z-PINP decreased (p <compared to untreated patients). In 20.6% of patients one or more morphometric vertebral deformities found. Conclusions: Hip BMD is normal in patients with sarcoidosis, despite an increased bone turnover. may imply that in sarcoidosis mechanisms are involved that compensate for the well-known effects of tokines in inflammatory diseases on osteoclastogenesis and bone resorption. Nonetheless, vertebral ties suggestive of fracture were found in a significant number of patients which indicates that patients sarcoidosis still have a relevant fracture risk