Energy Expenditure Promises Benefits for Diabetics

NEW YORK (Reuters Health) May 25 - Physical activity that expends more than 10 metabolic equivalents (METs) per hour per week will provide health advantages and reduced medical costs for patients with type 2 diabetes, according to Italian researchers. However, full benefits are not achieved unless more than 20 METs per hour per week are expended.

Senior author Dr. Pierpaolo De Feo and colleagues, from the University of Perugia note

that the results confirm that general recommendations of at least 30 minutes of moderate-intensity physical activity on most days are "also valid for type 2 diabetic subjects and demonstrate a significant dose-response relationship."

The findings, which appear in the June issue of Diabetes Care, are based on an analysis of data from 179 type 2 diabetic subjects who participated in a physical activity intervention. The subjects were divided into six groups based on the number of METs expended per hour per week.

The two groups that performed no more than 10 METs of exercise per hour per week experienced no change in HbA1c, blood pressure, total cholesterol, triglycerides, or heart disease risk. By contrast, the other four groups experienced improvements in all of these parameters.

In order to also achieve an improvement in body weight, waist circumference, heart rate, fasting glucose, serum LDL and HDL cholesterol, more than 20 METs per hour per week of activity was needed, the investigators note.

The groups with more than 10 METs per hour per week of exercise experienced a reduction in per capita yearly medication costs. The group with the lowest activity level (no METs) experienced a rise in costs and the group with the next lowest level (1 to 10 METS per hour per week) had no change in costs.

In a related editorial, Dr. James O. Hill, from the University of Colorado, Denver, comments that the results "provide an optimistic message about physical activity and type 2 diabetes. It isn't necessary for your patients to do a lot of strenuous exercise to reap health benefits. Even small increases in physical activity can help, and it seems possible to produce these changes in the majority of your patients."

Diabetes Care 2005;28:1295-1302,1524-1525.

Dairy Products May Lower Risk of Type 2 Diabetes in Men CME

May 10, 2005 — Men who have a high dairy intake have a lower risk of type 2 diabetes mellitus (DM), according to the results of a prospective study published in the May 9 issue of the Archives of Internal Medicine. The editorialist reviews the purported benefits of milk and dairy products.

"Diet and lifestyle modifications can substantially reduce the risk of type 2 diabetes," write Hyon K. Choi, MD, from Massachusetts General Hospital in Boston, and colleagues. "While a strong inverse association has been reported between dairy consumption and the insulin resistance syndrome among young obese adults, the relation between dairy intake and type 2 diabetes is unknown."

The investigators prospectively examined the relationship between dairy intake and incident cases of type 2 DM in 41,254 male participants with no history of DM, cardiovascular disease, and cancer when enrolled in the Health Professionals Follow-up Study.

During 12 years of follow-up, there were 1,243 incident cases of type 2 DM. Dairy intake was associated with a modestly lower risk of type 2 DM. Compared with men in the lowest quintile of dairy intake, the relative risk (RR) for type 2 DM in men in the top quintile of dairy intake was 0.77 (95% confidence interval [CI], 0.62 - 0.95; P for trend = .003), after adjustment for body mass index (BMI), physical activity, dietary factors, and other potential confounders.

For each serving-per-day increase in total dairy intake, there was a 9% lower risk for type 2 DM (multivariate RR, 0.91; 95% CI, 0.85 - 0.97). The corresponding RR was 0.88 (95% CI, 0.81 - 0.94) for low-fat dairy intake and 0.99 (95% CI, 0.91 - 1.07) for high-fat dairy intake. BMI did not affect this association (< 25 vs >/= 25 kg/m2; P for interaction, .57).

"Dietary patterns characterized by higher dairy intake, especially low-fat dairy intake, may lower the risk of type 2 diabetes in men," the authors write.

Study limitations include observational design, potential for unmeasured confounding, self-reporting of DM with possible underdiagnosis, and study population limited to men 40 years old and older with no history of type 2 DM.

The National Institutes of Health supported this study in part. The authors report no financial disclosures.

In an accompanying editorial, Janet C. King, PhD, from Children's Hospital Oakland Research Institute in California, calls this study "a further reminder of the potential importance of dairy intake and the continuing value of research in this area." She notes that milk contains amino acids, vitamins, minerals, and additional bioactive components.

"Many of these components protect individuals from exogenous stresses, toxins, and pathogens; encourage adaptation to the environment; and promote metabolic regulation, while other milk components cause negative effects in susceptible individuals," Dr. King writes. "Research shows that the role of dairy foods in health is very complex and probably varies with the genotype and phenotype of the individual."

Dr. King reports no financial conflicts of interest.

Arch Intern Med. 2005;165:975-976, 997-1003

Pioglitazone Slows Carotid Thickening in Diabetics

NEW YORK (Reuters Health) May 13 - Independent of its ability to improve glycemic control, pioglitazone therapy decreases carotid intima-media thickness (IMT) in patients with type 2 diabetes, according to a report in the May 17th issue of Circulation.

"We are encouraged by these results because the benefits seen with pioglitazone could, theoretically, lead to an overall reduction in the incidence of heart attack and stroke for people with type 2 diabetes," study co-author Dr. Thomas Forst, from the Institute for Clinical Research and Development in Mainz, Germany, said in a statement.

The findings stem from a study funded by Takeda Pharmaceuticals, which markets pioglitazone under the trade name Actos.

The study involved 173 patients with type 2 diabetes who were randomized to receive pioglitazone or glimepiride-based treatment for 24 weeks.

During the study period, patients in each group experienced similar improvements in glycemic control, based on HbA1c levels. However, only pioglitazone-treated subjects showed a significant reduction in carotid IMT at 12 and 24 weeks.

Insulin resistance improved significantly in the pioglitazone group, but not in the glimepiride group.

Further analysis showed that the drop in carotid IMT correlated with the improvement in insulin resistance, but was independent of changes in glycemic control, the authors note.

"Our results support the growing body of evidence for an anti-atherogenic effect of PPAR-gamma activators that reach beyond glycemic control and might imply prognostic benefits for patients treated with this class of drugs and especially for patients with type 2 diabetes," the authors conclude.

Circulation 2005;111:2525-2531.

Danish Study Outlines Risk Factors for Diabetic Maculopathy

By Earl R. Nichols FT. LAUDERDALE, FL -- May 9, 2005 -- According to a large Danish database, there does not appear to be a significant difference in the risk of developing diabetic maculopathy between patients with type 1 or type 2 diabetes, or type 2 patients who are insulin-dependent and who are not insulin-dependent. The risk is more or less similar, at 25.4 cases (a 5--year incidence rate of 11.9%) per thousand patient-years for patients with type 1 diabetes and 31.8 cases (a 5--year incidence rate of 14.7%) per thousand patient-years for those with type 2 diabetes. M. L. Laursen, MD, department of ophthalmology, Odense University Hospital, Odense, Denmark, presented the results in a poster session here at the Association for Research in Vision and Ophthalmology Annual Meeting. The longitudinal observational study was conducted at one diabetes clinic between 1997 and 2001 and examined a total of 1218 patients -- 696 with type 1 diabetes and 522 with type 2 diabetes. Patients had their eyes examined regularly using two-field, non-stereoscopic photography of the fundus. Over the course of the 5-year follow-up period, 47 patients with type 1 diabetes and 39 patients with type 2 diabetes developed maculopathy. Slightly more patients with insulin-dependent type 2 diabetes went on to develop maculopathy, but the difference was not significant when compared with those who were not insulin-dependent. Patients with type 1 diabetes were significantly younger than those with type 2 disease and had had diabetes for longer compared to type 2 diabetics (17.0 years vs. 9 years). When the database began collecting information, the patients were 40.3 years old in the type 1 diabetes group and 57.5 years old in the type 2 group. Those with type 1 disease were more likely to have normal body mass index, while those with type 2 disease were more likely to be overweight or obese. The main factors predicting which patients with type 1 diabetes were most likely to develop maculopathy were elevated triglycerides (risk ratio [RR] 1.29), haemoglobin 1Ac (RR 1.28) and vibration perception threshold, which is a measure of muscle and nerve fiber reactivity (RR 1.21) The factors most likely to be associated with progression to maculopathy among type 2 diabetics were duration of disease (RR 1.08), diastolic blood pressure (RR 1.20) and vibration perception threshold (RR 1.26) Other factors that were associated with a greater risk of developing maculopathy included elevated low-density lipoprotein cholesterol level and elevated total cholesterol level. Men were more likely to develop maculopathy than women (RR 1.61 and 1.44, respectively). Vibration perception threshold may be the most important of all these factors since it is known that mixed sensory autonomic neuropathy is the most common clinical subtype of diabetic neuropathy and that this may in turn reflect abnormalities in choroidal blood flow, which is highly innervated and regulated by the autonomic nervous system, the authors concluded. [Presentation title: Incidence of and Risk Factors for Diabetic Maculopathy in a Danish Photographic Screening Programme. Poster 393/B367]

Intense Insulin Therapy Does Not Improve Outcome After MI

NEW YORK (Reuters Health) May 03 - Intense metabolic control using insulin does not improve mortality and morbidity in type 2 diabetic patients after acute myocardial infarction, according to the results of a multicenter European study.

Insulin does not seem to be the only solution, but tight glucose control by any means is very important." Dr. Lars Ryden from the Karolinska Institute, Stockholm, told Reuters Health. He advises clinicians to "use all available tools to keep blood glucose...down."

Dr. Ryden and colleagues in the Diabetes and Insulin-Glucose Infusion in Acute MI 2 (DIGAMI 2) study compared three glucose management strategies in more than 1200 diabetic patients after suspected acute myocardial infarction.

These included acute insulin-glucose infusion followed by long-term insulin-based treatment; acute insulin-glucose infusion followed by standard glucose control; and routine management according to local practice.

Although blood glucose levels were lower with the first two strategies after the first 24 hours, the authors report, glucose control over time (blood glucose and glycosylated hemoglobin levels) did not differ among the three treatment approaches, Dr. Ryden's group reports in the April issue of the European Heart Journal.

Mortality also did not significantly differ among the three treatment groups. Secondary events (stroke, myocardial reinfarction, etc.) tended to be higher in the most intensive treatment program, but the differences did not reach statistical significance.

Although the three different treatment strategies had similar effects on mortality, "hyperglycemia remained one of the most important prognostic predictors," the investigators note.

"Future development of tools that will allow frequent and precise (non-invasive) measurement of blood glucose levels and, eventually, of an automated system for insulin-titrated tight blood glucose control will be of utmost importance," writes Dr. Greta Van den Berghe from Catholic University of Leuven, Belgium in a related editorial.

"We anxiously await the development and validation of such devices," Dr. Van den Berghe concluded.

Eur Heart J 2005;26:639-641,650-661.

Insulin Identified as Trigger for Type 1 Diabetes

WEDNESDAY, May 11 (HealthDay News) -- Insulin, the hormone most closely linked to diabetes, has turned out to be the cause of the inherited form of the blood sugar disease, researchers report.

For reasons that remain unclear, in patients with type 1 diabetes the body's immune T-cells react against insulin-producing cells in the pancreas -- effectively shutting them down and triggering disease onset.

After eight long years of painstaking----------------------------------------------(read online)

>Diabetic Neuropathies

Introduction

The diabetic neuropathies are heterogeneous, affecting different parts of the nervous system that present with diverse clinical manifestations. They may be focal or diffuse. Most common among the neuropathies are chronic sensorimotor distal symmetric polyneuropathy (DPN) and the autonomic neuropathies. DPN is a diagnosis of exclusion. The early recognition and appropriate management of neuropathy in the patient with diabetes is important for a number of reasons. 1 ) Nondiabetic neuropathies may be present in patients with diabetes. 2 ) A number of treatment options exist for symptomatic diabetic neuropathy. 3 ) Up to 50% of DPN may be asymptomatic, and patients are at risk of insensate injury to their feet. As >80% of amputations follow a foot ulcer or injury, early recognition of at-risk individuals, provision of education, and appropriate foot care may result in a reduced incidence of ulceration and consequently amputation. 4 ) Autonomic neuropathy may involve every system in the body. 5 ) Autonomic neuropathy causes substantial morbidity and increased mortality, particularly if cardiovascular autonomic neuropathy (CAN) is present. Treatment should be directed at underlying pathogenesis. Effective symptomatic treatments are available for the manifestations of DPN and autonomic neuropathy.

This statement is based on two recent technical reviews,[1,2] to which the reader is referred for detailed discussion and relevant references to the literature.---- cont online

Impact of MI, Diabetes on Overall Health Differs Between the Sexes

By Megan Rauscher

NEW YORK (Reuters Health) May 02 - In men myocardial infarction increases the risk of death from heart disease more so than diabetes, but in women diabetes is a greater mortality threat, according to results of a Finnish study reported May 3rd in the Journal of the American College of Cardiology.

"In general, diabetes is bad news for women," Dr. Gang Hu from National Public Health Institute and University of Helsinki told Reuters Health. "More aggressive management of diabetes to prevent cardiovascular disease may be needed, particularly in women," the researcher warned.

In the study, the investigators compared the effects of diabetes and MI on the risk of death in two cohorts of patients: a baseline cohort, which included 2416 patients with prior diabetes or MI who were followed for 12 years; and a follow-up cohort, which included 4315 patients who were diagnosed with incident diabetes or MI during follow-up and were further followed for 7.7 years after diagnosis.

Most previous studies only had a "single baseline measurement for the disease status of diabetes and MI," Dr. Hu pointed out.

In the baseline cohort, men with prior MI had a 20% to 80% increased risk of death from CHD or any cause, whereas women with prior MI had a 43% to 45% decreased risk of CHD or total mortality compared with men and women with prior diabetes.

In the follow-up cohort, men and women with incident MI had a greater risk of dying from heart disease, with hazard ratios of 2.15 and 1.65, respectively, compared with men and women with incident diabetes.

Total mortality, however, was similar between subjects with incident diabetes and MI during follow up, Dr. Hu said.

For people with incident MI, CHD is "the major cause of death," Dr. Hu explained, whereas people with incident diabetes may be at increased risk of dying from CHD, stroke, cancer, kidney disease, infection and other causes. Thus, total mortality is similar between subjects with incident diabetes and MI, which highlights the importance of diabetes on overall health, the researcher added.

In a statement, Dr. Christiane E. Angermann, from the University of Wurzburg in Germany said this study provides "yet another strong argument for the necessity to consider gender-related differences between men and women regarding the impact of risk factors, while designing guidelines not only for diagnosis and therapy, but also, and in particular, for the prevention of cardiovascular disease."

J Am Coll Cardiol 2005;45:1413-1418.