A randomised trial comparing weight loss with aerobic exercise in overweight individuals with coronary artery disease: The CUT-IT trial.

BACKGROUND: We aimed to compare the effect of aerobic interval training (AIT) versus a low energy diet (LED) on physical fitness, body composition, cardiovascular risk factors and symptoms in overweight individuals with coronary artery disease (CAD). METHODS AND DESIGN: Seventy non-diabetic participants with CAD, a BMI>28 kg/m(2) and aged 45 to 75 years were randomised to 12 weeks' AIT at 90% peak heart rate three times a week or LED (800-1000 kcal/day) for 8-10 weeks followed by 2-4 weeks' weight maintenance diet. RESULTS: Twenty-six (74%) AIT and 29 (83%) LED participants completed intervention per protocol. VO2peak (mL/kg fat free mass(0.67)/min) increased by 10.4% (p = 0.002) following AIT, whereas no change was observed after LED (-3.0%, p = 0.095). The LED group lost 10.6% body weight and 26.6% body fat mass (p < 0.001) compared to 1.6% (p = 0.002) and 5.5% (p < 0.001) following AIT. Waist circumference and visceral abdominal fat were reduced by both interventions but were most pronounced following LED (between-group, p < 0.001). Total cholesterol, non-HDL-C and triglycerides decreased significantly in both groups whereas HDL-C and blood pressure were unchanged. Six participants had their antihypertensive treatment reduced following LED (between-group, p = 0.032). Canadian Cardiovascular Society (CCS), New York Heart Association (NYHA) and anxiety scores were improved, while depressive symptoms remained unchanged. Intention-to-treat analyses including 65 participants (93%) were similar to per protocol analysis. CONCLUSION: Both interventions were feasible and effective in achieving the desired effects. LED was superior in improving body composition and blood pressure, whereas effects on lipids and symptoms were similar in the two groups. Thus, both AIT and LED improve the cardiovascular risk profile in overweight individuals with contemporarily treated CAD.

Resting, night-time, and 24 h heart rate as markers of cardiovascular risk in middle-aged and elderly men and women with no apparent heart disease.

AIMS: Increased heart rate (HR) is a predictor of all-cause and cardiovascular (CV) mortality. We tested which measure of HR had the strongest prognostic value in a population with no apparent heart disease. METHODS AND RESULTS: Six hundred and fifty-three men and women between the age of 55 and 75 years were included in the Copenhagen Holter Study and underwent 48 h ambulatory electrocardiographic (ECG) monitoring. Resting HR was measured after at least 10 min of rest. Twenty-four-hour HR was derived from the mean time between normal-to-normal RR intervals (MEANNN). Night-time HR was derived from a 15 min sequence between 2:00 and 2:15 a.m. The median follow-up time was 76 months, and an adverse outcome was defined as all-cause mortality and the combined endpoint of CV death, acute myocardial infarction (AMI), and revascularization. All three measures of HR were significantly associated with all-cause mortality, also after adjustment for conventional risk factors. We found an association between all three measures of HR and CV events in analyses adjusted for sex and age. However, when adjusting for CV risk factors, the association with resting HR and 24 h HR disappeared. In a fully adjusted model, only night-time HR remained in the model, hazard ratio = 1.17 (1.05-1.30), P = 0.005. CONCLUSION: In middle-aged subjects with no apparent heart disease, all measures of increased HR were associated with increased mortality and CV risk. However, night-time HR was the only parameter with prognostic importance after multivariable adjustment.

A 2-wk reduction of ambulatory activity attenuates peripheral insulin sensitivity.

US adults take between approximately 2,000 and approximately 12,000 steps per day, a wide range of ambulatory activity that at the low range could increase risk for developing chronic metabolic diseases. Dramatic reductions in physical activity induce insulin resistance; however, it is uncertain if and how low ambulatory activity would influence peripheral insulin sensitivity. We aimed to explore if healthy, nonexercising subjects who went from a normal to a low level of ambulatory activity for 2 wk would display metabolic alterations including reduced peripheral insulin sensitivity. To do this, ten healthy young men decreased their daily activity level from a mean of 10,501+/-808 to 1,344+/-33 steps/day for 2 wk. Hyperinsulinemic-euglycemic clamps with stable isotopes and muscle biopsies, maximal oxygen consumption (VO2 max) tests, and blood samples were performed pre- and postintervention. A reduced number of daily steps induced a significant reduction of 17% in the glucose infusion rate (GIR) during the clamp. This reduction was due to a decline in peripheral insulin sensitivity with no effect on hepatic endogenous glucose production. The insulin-stimulated ratio of pAktthr308/total Akt decreased after step reduction, with a post hoc analysis revealing the most pronounced effect after 4 h of insulin infusion. In addition, the 2-wk period induced a 7% decline in VO2 max (ml/min; cardiovascular fitness). Lean mass of legs, but not arms and trunk, decreased concurrently. Taken together, one possible biological cause for the public health problem of Type 2 diabetes has been identified. Reduced ambulatory activity for 2 wk in healthy, nonexercising young men significantly reduced peripheral insulin sensitivity, cardiovascular fitness, and lean leg mass.