A combination of aerobic and resistance training helps improve glycated hemoglobin (HbA1c) levels in patients with Type 2 diabetes compared with no exercise, report researchers.

Notably, only the combination of exercises was effective with no significant improvement in HbA1c seen in diabetics who participated in aerobic or resistance training alone.

“Although it is generally accepted that regular exercise provides substantial health benefits to individuals with Type 2 diabetes, the exact exercise prescription in terms of type (aerobic vs resistance vs both) is unclear,” write Timothy Church (Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA) and colleagues.

To investigate further, Church and team recruited 262 sedentary men and women, aged 55.8 years on average, with Type 2 diabetes and HbA1c levels higher than 6.5% to take part in the Health Benefits of Aerobic and Resistance Training in individuals with Type 2 diabetes (HART-D) study, which took place over 9 months.

The researchers assigned 41 individuals to a no-exercise control group, 73 to resistance training (3 days/week), 72 to aerobic exercise (energy expenditure of 12 kcal/kg/week), and 76 to a combination of aerobic (10 kcal/kg/week), and resistance training (2 days/week).

Compared with controls, the team reports in JAMA that patients in the combination exercise group had a statistically significant mean reduction in HbA1c of 0.34% at study completion.

In contrast, HbA1c was reduced by only 0.16% and 0.24% in the resistance and aerobic training alone groups, respectively; neither of these decreases were significant.

Of note, the combination exercise group participants were the only ones to improve their maximum oxygen consumption and they also lost the most fat mass compared with controls.

Ronald Sigal and Glen Kenny (University of Ottawa, Ontario, Canada), the authors of an accompanying editorial, commented: “Based on the results of the HART-D trial, patients with Type 2 diabetes who wish to maximize the effects of exercise on their glycemic control should perform both aerobic and resistance exercise.”

They concluded: “The HART-D trial clarifies that, given a specific amount of time to invest in exercise, it is more beneficial to devote some time to each form of exercise rather than devoting all the time to just one form of exercise.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Free abstract

Patients with heart failure (HF) have an increased risk for Type 2 diabetes, in a severity-dependent manner, compared with individuals without the condition, show study results.

It is known that diabetes increases the risk for HF, but whether the opposite is also true is less clear, say researchers.

Charlotte Andersson (University of Copenhagen, Denmark) and colleagues recruited 50,874 patients who were discharged after a first-time myocardial infarction between 1997 and 2006. They had not previously been treated with glucose lowering medication or loop diuretics.

The researchers classified 3006 patients as having mild (loop diuretic dosage [LDD] 40 mg/day or less), 5383 as having moderate (LDD 40-120 mg/day), and 1127 as having severe (more than 120 mg/day) HF.

During the follow-up period (between recruitment and 2006, first antihyperglycemic medication prescription, or death), 2531 patients developed Type 2 diabetes. The team found that increasing severity of HF increased the risk for diabetes, but use of renin-angiotensin system inhibitors (RASi) weakened the association.

Compared with patients with no HF, those with mild, moderate, and severe HF using RASis had a significant 34%, 63%, and 68% increased risk for developing diabetes, respectively. Without RASi treatment, the risks were higher, with 1.45-, 1.90-, and 3.02-fold increased risks for diabetes in the corresponding three groups.

“Because early and aggressive evidence-based therapy is thought to reduce the morbidity and mortality of patients with diabetes, our results emphasize the importance of diabetes prevention through lifestyle interventions and of continuous monitoring for the development of diabetes in patients with HF,” write the authors.

They conclude: “Furthermore, our study suggests that RASi should be considered in HF patients after MI for attenuation of the risk of diabetes.”

The results of this study are published in the European Journal of Heart Failure.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Free abstract

Statins can reduce the risk for cardiovascular disease (CVD) by 40-50% in Chinese patients with Type 2 diabetes, research suggests.

The study also showed that high levels of low-density lipoprotein (LDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol predicted incident CVD. In contrast, triglycerides had no significant predictive value.

The findings come from 4521 patients with Type 2 diabetes but without a history of CVD who were naïve to lipid-regulating drugs and were recruited into the Hong Kong Diabetes Registry between 1996 and 2005.

During a median follow up of 4.9 years, 371 developed CVD, report Juliana Chan (The Chinese University of Hong Kong) and colleagues in the journal Cardiovascular Diabetology.

The optimal LDL-cholesterol level for CVD risk was less than 3 mmol/l (116.0 mg/dl), and participants with levels above this had a multivariate-adjusted hazard ratio (HR) of 1.36 compared with lower levels.

HDL cholesterol exhibited a continuous and linear relationship with this risk, with each 1 mmol/l increase associated with a 1% reduction in CVD risk.

Statin use was associated with an HR of 0.66 for CVD compared with no such use, but the risk reduction with fibrates was rendered insignificant after adjusting for confounders.

A sub-analysis showed that statins were associated with a HR of 0.60 in patients with high LDL cholesterol levels of 3.0 mmol/l or more and 0.49 in those with low HDL cholesterol levels, with the latter identified as less than 1.0 mmol/l (38.7 mg/dl) in men or 1.3 mmol/l (50.3 mg/dl) in women.

Only statins were linked with a reduction in incident CVD in patients with metabolic syndrome, with an HR of 0.58. Among patients with LDL-cholesterol levels of less than 3 mmol/l, fibrates were associated with a HR of 0.34 for CVD, which was of borderline significance.

The researchers conclude: “Given the narrow risk-benefit ratio of intensive blood glucose lowering in Type 2 diabetic patients, especially those with long disease duration who often have silent ischemic disease, patients and health-care professionals must be aware of the importance of attaining recommended lipid goals to reduce CVD risks.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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