Coronary microvascular function, insulin sensitivity and body composition in predicting exercise capacity in overweight patients with coronary artery disease.

BACKGROUND: Coronary artery disease (CAD) has a negative impact on exercise capacity. The aim of this study was to determine how coronary microvascular function, glucose metabolism and body composition contribute to exercise capacity in overweight patients with CAD and without diabetes. METHODS: Sixty-five non-diabetic, overweight patients with stable CAD, BMI 28-40 kg/m(2) and left ventricular ejection fraction (LVEF) above 35 % were recruited. A 3-hour oral glucose tolerance test was used to evaluate glucose metabolism. Peak aerobic exercise capacity (VO2peak) was assessed by a cardiopulmonary exercise test. Body composition was determined by whole body dual-energy X-ray absorptiometry scan and magnetic resonance imaging. Coronary flow reserve (CFR) assessed by transthoracic Doppler echocardiography was used as a measure of microvascular function. RESULTS: Median BMI was 31.3 and 72 % had impaired glucose tolerance or impaired fasting glucose. VO2peak adjusted for fat free mass was correlated with CFR (r = 0.41, p = 0.0007), LVEF (r = 0.33, p = 0.008) and left ventricular end-diastolic volume (EDV) (r = 0.32, p = 0.01) while it was only weakly linked to measures of glucose metabolism and body composition. CFR, EDV and LVEF remained independent predictors of VO2peak in multivariable regression analysis. CONCLUSION: The study established CFR, EDV and LVEF as independent predictors of VO2peak in overweight CAD patients with no or only mild functional symptoms and a LVEF > 35 %. Glucose metabolism and body composition had minor impact on VO2peak. The findings suggest that central hemodynamic factors are important in limiting exercise capacity in overweight non-diabetic CAD patients.

[Christmas article: Christmas-related exogenous palmar hyperpigmentation].

On a routine control for macular degeneration, a 90-year-old man presented with hyperpigmentation of the skin on both palms and bilateral thumbnail discolouration. He was otherwise asymptomatic. He had been shelling walnuts to store in his freezer for use as Christmas cake decorations. Shortly after, he noticed the cutaneous colour change in both palms. The condition resolved spontaneously over a period of about three weeks. Outbreaks of walnut shell-related hyperpigmentation tend to occur during the cake decorating season, especially at Christmas time, and often present with so-called "cake decorators' palms".

Liraglutide improves the beta-cell function without increasing insulin secretion during a mixed meal in patients, who exhibit well-controlled type 2 diabetes and coronary artery disease.

BACKGROUND: Hyperinsulinemia aggravates insulin resistance and cardio-vascular disease. How the insulinotropic glucagon-like peptide-1 receptor agonist liraglutide in a physiologic post-prandial setting may act on pancreatic alpha and beta-cell function in patients with coronary artery disease (CAD) and type 2 diabetes (T2DM) is less clear. METHODS: Insulin resistant patients with established CAD and newly diagnosed well-controlled T2DM were recruited to a placebo-controlled, cross-over trial with two treatment periods of 12 weeks and a 2 weeks wash-out period before and in-between. Treatment was liraglutide or placebo titrated from 0.6 mg q.d. to 1.8 mg q.d. within 4 weeks and metformin titrated from 500 mg b.i.d to 1000 mg b.i.d. within 4 weeks. Before and after intervention in both 12 weeks periods insulin, C-peptide, glucose, and glucagon were measured during a meal test. Beta-cell function derived from the oral glucose tolerance setting was calculated as changes in insulin secretion per unit changes in glucose concentration (Btotal) and whole-body insulin resistance using ISIcomposite. RESULTS: Liraglutide increased the disposition index [Btotal × ISIcomposite, by 40% (n = 24, p < 0.001)] compared to placebo. Post-prandial insulin and glucose was reduced by metformin in combination with liraglutide and differed, but not significantly different from placebo, moreover, glucagon concentration was unaffected. Additionally, insulin clearance tended to increase during liraglutide therapy (n = 26, p = 0.06). CONCLUSIONS: The insulinotropic drug liraglutide may without increasing the insulin concentration reduce postprandial glucose but not glucagon excursions and improve beta-cell function in newly diagnosed and well-controlled T2DM.Trial registration Clinicaltrials.gov ID: NCT01595789.

A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease.

BACKGROUND: Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD patients. METHODS AND RESULTS: Seventy non-diabetic patients (BMI 28-40 kg × m(-2), age 45-75 years) were randomised to 12 weeks' AIT (three weekly sessions lasting 38 min with ≈ 16 min at 85-90% of VO2peak) or low energy diet (LED, 800-1000 kcal/day). Per protocol adherence was defined by training-attendance ≥ 60% and weight loss ≥ 5%, respectively. CFR was assessed by Doppler echocardiography of the LAD. Peripheral vascular function was assessed by arterial tonometry as reactive hyperaemia index (RHI) and augmentation index. Most participants had impaired CFR with a mean CFR of 2.38 (SD 0.59). Twenty-six AIT and 24 LED participants completed the study per protocol with valid CFR measurements. AIT resulted in a 10.4% improvement in VO2peak and LED in a 10.6% weight loss (between group differences both P<0.001). CFR increased by 0.26 (95%CI 0.04;0.48) after AIT and by 0.39 (95%CI 0.13;0.65) after LED without significant between-group difference (-0.13 (95%CI -0.45;0.20)). RHI and augmentation index remained unchanged after both interventions (P>0.50). Intention-to-treat analyses showed similar results. CONCLUSIONS: 12 weeks' AIT and LED increased CFR by comparable magnitude; thus both interventions might impact prognosis of CAD through improvement of coronary microvascular function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01724567.

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.

A randomized trial comparing the effect of weight loss and exercise training on insulin sensitivity and glucose metabolism in coronary artery disease.

AIM: The majority of patients with coronary artery disease (CAD) exhibit abnormal glucose metabolism, which is associated with mortality even at non-diabetic glucose levels. This trial aims to compare the effects of a considerable weight loss and exercise with limited weight loss on glucose metabolism in prediabetic, CAD patients. METHODS AND RESULTS: Seventy non-diabetic participants with CAD, BMI 28-40 kg/m(2), age 45-75 years were randomized to 12 weeks' aerobic interval training (AIT) at 90% peak heart rate three times weekly or a low energy diet (LED, 800-1,000 kcal/day) for 8-10 weeks followed by 2-4 weeks' weight maintenance diet. Glucose tolerance, insulin action, ß-cell function and suppression of lipolysis were assessed using a 3-h oral glucose tolerance test. ISI-composite and ISI-HOMA (=1/HOMA-IR) were calculated as surrogate measures of whole-body and hepatic insulin sensitivity, respectively. Magnetic resonance imaging estimated abdominal adipose tissue. Twenty-six (74%) AIT and 29 (83%) LED participants completed intervention per protocol. LED increased ISI-composite by 55% and ISI-HOMA by 70% (p<0.01) while AIT did not change insulin sensitivity (p>0.7) revealing a significant difference between the groups (p<0.05). No concurrent significant changes in lipolysis, ß-cell responsiveness or insulin clearance were seen. Changes in ISI-HOMA and ISI-composite were associated with reduced visceral abdominal fat, waist circumference and body weight. Intention-to-treat analyses (n=64) yielded similar results. CONCLUSION: LED is superior to AIT in improving insulin sensitivity in prediabetic CAD patients. Changes in insulin sensitivity are associated with decreased visceral abdominal fat, waist circumference and body weight.