Blood Sugar Imbalance, Diabetes Update

November is American Diabetes Month. Considering that public health experts predict that one in three US adults may have diabetes by 2050, we thought it prudent to pay homage by sharing with the you what we have learned recently.

Diabetic Retinopathy
A new study has found that patients with diabetic retinopathy, especially the proliferative type, are more likely to have insufficient serum vitamin D levels than people without diabetes, suggesting a link between vitamin D deficiency and one of the leading causes of blindness in adults. The findings were presented at the American Academy of Ophthalmology and Middle East Africa Council of Ophthalmology 2010 Joint Meeting.

Mean levels of 25-hydroxyvitamin D in adults with type 2 diabetes were well below 30 ng/mL, the cutoff the researchers used to define vitamin D "insufficiency" (deficiency). More than 75% of patients with diabetic retinopathy were deficient in vitamin D. They excluded patients with type 1 diabetes, vitamin D intake greater than 1000 IU/day, and disorders that change the metabolism of vitamin D. To minimize differences in sun exposure, the investigators performed vitamin D testing for all subjects from December 2009 through March 2010.

People with no eye disease had the highest serum vitamin D levels and those with proliferative retinopathy had the lowest levels (mean, 21.1 ng/mL).

After performing a linear multivariate analysis to control for potential confounders, the authors found only 1 factor that remained statistically significant: daily multivitamin use. "The use of daily multivitamins was somewhat protective against the development of vitamin D insufficiency," researchers said. However, even those who took daily multivitamins had a 44% incidence of vitamin D insufficiency because the mean intake of vitamin D from the multivitamins was less than the recommended daily intake of 400 IU.

Potential Link Between Obesity and Diabetes Explained?
Inflammation-causing cells in fat tissue may explain the link between obesity and diabetes. The discovery may open the way for new anti-inflammatory treatments that prevent insulin resistance (where the body is unable to respond to and use the insulin it produces) and other complications associated with obesity.

Macrophages, white blood cells derived from the bone marrow, are immune cells that normally respond to infections. In obese people, macrophages move into the fat tissue where they cause inflammation and release cytokines, which are chemical messenger molecules used by immune cells to communicate. Certain cytokines cause cells to become resistant to the effects of the hormone insulin, leading to diabetes and heart disease.

The findings, published in the journal Diabetes, provide the first evidence in humans that macrophages in the fat tissue are producing cytokines that prevent cells from appropriately responding to the presence of insulin. Encouragingly, the study also showed that when obese people lost weight the macrophages in the fat tissue disappeared, as did the risk of developing insulin resistance and diabetes.

If Harvard researchers are correct in their assumption that 42% of Americans will be obese before the epidemic reaches its peak (it is currently at 34%), the link to diabetes will get worse before it gets better.

Coffee, Tea, Alcohol and Risk of Diabetes in African American Women
The study included 46,906 Black Women's Health Study participants aged 30–69 y at baseline in 1995. During 12 y of follow-up, there were 3671 incident cases of type 2 diabetes. Intakes of decaffeinated coffee and tea were not associated with risk of diabetes. However, women who drank moderate amounts of caffeinated coffee or alcohol had a reduced risk of type 2 diabetes. American Journal of Clinical Nutrition, October 2010

Women With Polycystic Ovary Syndrome (PCOS) Improve With Low Glycemic Diet
Researchers compared changes in insulin sensitivity and clinical outcomes after similar weight losses after consumption of a low-GI diet compared with a conventional healthy diet in women with PCOS. Overweight and obese premenopausal women with PCOS consumed either a low-GI diet or a macronutrient-matched healthy diet and for 12 mo or until they achieved a 7% weight loss. Among completers, oral glucose-intolerance test improved more with the low-GI diet than with the conventional healthy diet. There was even greater improvement in the oral-glucose tolerance test among women prescribed both metformin and the low-GI diet. Compared with women who consumed the conventional healthy diet, more women who consumed the low-GI diet showed improved menstrual cyclicity (95% compared with 63%, respectively). Among the biochemical measures, only serum fibrinogen concentrations showed significant differences between diets. To the best of our knowledge, this study provides the first objective evidence to justify the use of low-GI diets in the management of PCOS.

Corticosteroid Use and Diabetes Risk
The use of inhaled corticosteroids, whether for asthma or chronic obstructive pulmonary disease (COPD), increases the likelihood of diabetes onset and diabetes progression, according to a study in The American Journal of Medicine. Systemic corticosteroids are known to increase diabetes risk, but the effects of inhaled corticosteroids are unknown. Of 388,584 patients newly treated for respiratory disease from 1990 to 2005 and followed through 2007, use of inhaled corticosteroids was associated with a significant 34% increase in the rate of diabetes. It translates into an additional 5 cases of diabetes per 1000 patients every year from the medication.

Father's Status at Time of Conception Linked to Diabetes Risk in Offspring
Medical researchers have for the first time shown a link between a father's weight and diet at the time of conception and an increased risk of diabetes in his offspring. The finding, reported in the journal Nature, is the first in any species to show that paternal exposure to a high-fat diet initiates progression to metabolic disease in the next generation. While researchers are aware that overweight women are more likely to have overweight babies, and that a woman's weight before and during pregnancy can play a role in future disease in her children, partly due to the critical role the intrauterine environment plays in development, the impact of the father's environment -- in terms of his diet -- on his offspring had not been investigated.

Paternal environmental factors such as diet and weight are important contributors to disease in the next generation. The research showed that overweight fathers can play a role in "programming" epigenetic changes in their offspring, possibly through effects on their sperm caused by their consumption of high-fat food.

Sugar-Sweetened Beverages Increase Risk of Diabetes
A new study has found that regular consumption of soda and other sugar-sweetened beverages is associated with a clear and consistently greater risk of metabolic syndrome and type 2 diabetes. According to the Harvard School of Public Health (HSPH) researchers, the study provides empirical evidence that intake of sugary beverages should be limited to reduce risk of these conditions. In the journal Diabetes Care, the researchers claim that many previous studies have examined the relationship between sugar-sweetened beverages and risk of diabetes, and most have found positive associations but their study provides an overall picture of the magnitude of risk and the consistency of the evidence.

The studies included more than 300,000 participants and 15,043 cases of type 2 diabetes and 19,431 participants and 5,803 cases of metabolic syndrome. The findings showed that drinking one to two sugary drinks per day increased the risk of type 2 diabetes by 26% and the risk of metabolic syndrome by 20% compared with those who consumed less than one sugary drink per month.

Potassium Deficiency, Diabetes Link
Serum potassium level is an independent predictor of incident type 2 diabetes mellitus, according to the Archives of Internal Medicine. Serum potassium levels affect insulin secretion by pancreatic β-cells, and hypokalemia associated with diuretic use has been associated with dysglycemia. Researchers hypothesized that adults with lower serum potassium levels and lower dietary potassium intake are at higher risk for incident diabetes, independent of diuretic use. Data from 12,209 participants who had 9 years of in-person follow-up and 17 years of telephone follow-up. showed that incident diabetes developed in 1475 participants during 9 years of in-person follow-up. Serum potassium level was inversely associated with the risk for incident diabetes, based on multivariate analyses. Compared with adults who had a high-normal serum potassium level, those with serum potassium levels less than 4.0 mEq/L, 4.0 to less than 4.5 mEq/L, and 4.5 to less than 5.0 mEq/L had a higher incidence of diabetes. During an additional 8 years of telephone follow-up, those with a serum potassium level of less than 5.0 mEq/L had a persistently increased risk for self-reported diabetes. Low dietary potassium intake was significantly associated with the risk for incident diabetes.

The association between increased risk of diabetes and low serum potassium levels seen in this cohort should be assessed in other populations.

Mediterranean Diet Halves Diabetes Risk
Use of the Mediterranean diet among nondiabetics at high cardiovascular risk halved the incidence of new-onset diabetes over four years compared with a low-fat diet. This is the first randomized clinical trial to look specifically at use of the Mediterranean diet for the prevention of diabetes, according to researchers of the study in Diabetes Care.

The diabetes risk reduction occurred in the absence of significant changes in body weight or physical activity, so the reduction can be attributed only to the diet, not to weight loss. Energy restriction was not advised in the trial, nor was physical activity promoted. The findings indicate that a non–energy-restricted traditional Mediterranean diet high in unsaturated fat could be a useful tool for preventing diabetes.

Aspirin Should Not Be a Primary Preventive Diabetes Therapy
According to US Pharmacist, low-dose aspirin remains a secondary prevention strategy in patients with diabetes and a history of CVD, yet it is no longer advocated as primary prevention for all patients aged 40 years and older with diabetes. Low-dose aspirin is now recommended for patients with an increased CV risk (10-year risk >10%), including men older than 50 years and women older than 60 years with at least one additional major risk factor. As far as we are concerned, there are other options besides pharmaceuticals that are just as effective than aspirin for this group.