Results from the EDIC study show that the benefits of tight glucose control on cardiac autonomic neuropathy (CAN) can persist for up to 14 years.

When the Diabetes Control and Complications Trial (DCCT) ended, participants were followed-up in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. Blood glucose levels in the intensive treatment group rose in participants and by the fifth year of follow-up, the difference in glycated hemoglobin (HbA1c) between the intensive and conventional treatment groups was no longer statistically significant.

Despite this, results from the EDIC study demonstrated persistent benefits of prior intensive therapy on retinopathy and nephropathy compared with conventional therapy.

Rodica Pop-Busui (University of Michigan, Ann Arbor, USA) and colleagues evaluated whether similar benefits apply to the prevalence and incidence of CAN 13 to 14 years after completion of the DCCT.

Autonomic measures assessed at baseline and biennially in the DCCT including R-R variation with paced breathing, Valsalva ratio, and postural blood pressure changes (DCCT composite definition of CAN) were repeated in 1211 participants during year 13 to 14 of the EDIC study follow-up.

The primary end point was incidence of CAN using the composite definition among those without CAN at DCCT close.

“During EDIC, CAN progressed substantially in both treatment groups, but the prevalence and incidence of CAN in EDIC year 13/14 remained significantly lower in the former intensive group than in the former conventional group, despite similar levels of glycemic control,” report the authors in the journal Circulation.

The prevalence of CAN in the former intensive and conventional treatment groups was 28.9% and 35.2%, respectively.

Virtually all of the difference between treatment groups in the incidence of CAN was explained by differences in HbA1c levels between groups.

The authors note that even after adjustment for the presence of CAN at the end of the DCCT, there were persistent beneficial effects of intensive versus conventional therapy at the end of the EDIC study follow-up. “A metabolic memory effect has occurred for measures of CAN as previously observed for retinopathy and nephropathy,” they write.

CAN is associated with an increased frequency of silent myocardial ischemia and major cardiovascular events and is a predictor for cardiovascular mortality. However, despite an increase in CAN prevalence in both treatment groups, only a relatively small number of participants reported symptoms consistent with autonomic neuropathy in EDIC study year 13/14.

“Our results support the initiation of intensive treatment of Type 1 diabetes mellitus as early as is safely possible to provide durable protection from the development and progression of diabetic complications,” conclude the authors.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009

Free abstract

Women who experience gestational diabetes have a greatly increased risk for developing Type 2 diabetes later in life compared with those who experience a normoglycemic pregnancy, report researchers in The Lancet.

“The increase in relative risk of future Type 2 diabetes after gestational diabetes in our systematic review and meta-analysis provides an incentive for women with a history of gestational diabetes to attend postpartum and continuous assessments for glucose tolerance,” say David Williams (University College London, UK) and co-authors.

For the study, the researchers identified 20 studies including a total of 675,455 women, of whom 10,859 subsequently developed Type 2 diabetes.

The investigators report that women with gestational diabetes had a 7.43-fold increase in relative risk for developing Type 2 diabetes compared with women who had a normoglycemic pregnancy.

The strength of the association and the knowledge that many of the risk factors are the same, suggest that the two disorders might have an overlapping cause, say the researchers.

Furthermore, the authors say that results of candidate gene studies give support to this hypothesis.

“A history of gestational diabetes therefore provides a low-cost, natural screening test for future Type 2 diabetes,” conclude Williams et al.

In an accompanying comment, Rhonda Bentley??”Lewis (Brigham and Women’s Hospital, Boston, Massachusetts, USA) said: “The present task is to ensure that this information is disseminated to clinicians and that the information is used to target prevention efforts to those who have had gestational diabetes… we as clinicians are afforded the rare opportunity to alter the natural course of disease and change the future health of women today.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009

Free abstract

Hypoglycemia is an abnormally low blood sugar level. This can be caused by too much insulin, too little food, or too much physical activity. Most incidents occur before meals but they may occur at any time of the day or night. Anything under 75 mg/dl (4 mmol/l) is too low; this is when symptoms start to show.

There is nothing available like our body which constantly measures our blood glucose and responds with the appropriate amount of insulin.

The most common cause for the level to drop is through the use of injectable-insulin or insulin-stimulating pills. So you need to co-ordinate the time of your food intake with your medications, especially injections.

Different drugs are potent at different times:

• rapid onset: (eg.Humalog, Novolog), acts within five minutes, peak action is between one and two hours, duration is up to five hours. As it wears off quickly, there is less chance of hypoglycemia.
• short-acting or soluble: (eg. Actrapid, Humulin R), starts to lower blood-sugars in thirty minutes, peaks at three hours and stops acting at about six to eight hours. It’s a good idea to have a snack two to three hours after your meal.
• intermediate-acting NPH or Lente: (eg. Humulin NPH, Isophane NPH, Humulin L), begins lowering glucose within two hours and continues to be active for ten to twelve hours. This means there is always a low level of insulin in your body. You may need a morning and afternoon snack.
• long-acting Ultralente: (eg. Hypurin Isophane, Humulin UL), begins to act within a period of six hours and a low level of activity remains for up to thirty-six hours.

There are also mixed-insulins available; the peak and duration is a combination of both drugs and, if you use this type, you most likely will need to snack between meals and before bedtime.

Consistency in mealtimes and meal sizes:

• it is better to space your meals and snacks throughout the day rather than skip them and just eat one or two large meals.
• your diet plays a major role in helping you to avoid hypoglycemia. Have a snack mid-morning and one mid-afternoon, as well as your usual three meals.
• include sufficient carbohydrate in your meal plan.
• you are likely to require a lower dose when fasting (eg. during Ramadan). You would need to work this out with your health care provider.

Check your blood sugar level before exercising:

• exercise generally lowers your level also
• check before starting to exercise
• if it’s low, have a snack before commencing

Weight loss:

• this is when your insulin dose will need to be reduced as it works more effectively when you have less body fat.

If you have managed to lose weight, congratulations! A healthy diet, weight loss and exercise is still the first choice of treatment for type 2 diabetes.