Reuters reports that Zarlink Semiconductor Inc of Ottawa has unveiled a ground-breaking chip for medical devices that it says could let doctors monitor a patient’s pacemaker or even control a diabetic’s insulin dosage from miles away. It is the first chip designed specifically for in-body communication systems, which wirelessly link implanted devices via base stations to a doctor or hospital. They see the device as being used in implanted blood glucose meters, which control insulin. Several companies are working on an implantable glucose sensor and even implanted insulin pump. Of interest is that this chip transmits about 10 times the data of rival products consuming about 20% of the power and when not being used to transmit or receive the chip essentially sleeps.
A new gene suspected to contribute to autoimmune diseases such as type 1 diabetes and lupus has been discovered by Australia National University immunologists. The researchers found that a mutation in the gene, which they have named, Roquin, causes the body’s infection fighters–T-cells-to attack their own tissue; the realization opening the way to explore treatments that target the mutation. Studies of the gene are underway in patients with lupus and type 1 diabetes to determine whether the same or similar mutations observed in laboratory mice are present in humans. “It’s one very small part of the genome that has proven a very big breakthrough. That single nucleotide change reduces the function of an autoimmunity gene and protein that was hitherto entirely unknown. According to Professor Christopher Goodnow, the Head of the Immunogenomics Laboratory the John Curtin School of Medical Research and Director of the Australian Phenomics Facility, the discovery hinged upon identifying a single letter change in the DNA code of Roquin.
B– Cell function across the spectrum of glucose tolerance in obese youth, in Diabetes 54:1735-1743, 2005, by Ram Weiss et al examined the profile and roles of insulin secretion and the role of proinsulin processing across the spectrum of glucose tolerance in obese youth. Thirty obese youth with normal glucose tolerance (NGT), 22 with impaired glucose tolerance (IGT), and 10 with type 2 diabetes were studied. The three groups had comparable anthropometric measure and insulin sensitivity. The glucose of first-phase secretion showed significant stepwise decline from NGT to IGT and from IGT to type 2 diabetes. The glucose sensitivity of the second-phase secretion was similar in NGT and IGT subjects yet significantly lower in subjects with type 2 diabetes. Proinsulin-to-insulin ratios were comparable during first-and second-phase secretions between subjects with NGT and IGT and were significantly increased in type 2 diabetes. Obese youth with IGT have a significant defect in first-phase secretion, while a defect in second-phase secretion and Proinsulin processing is specific for type 2 diabetes in this age group.
Caffeine may reduce nocturnal hypoglycemia in type 1 diabetes by Laurie Barclay in the June issue of Diabetes Care examines the benefits of regular caffeine ingestion in patients with type 1 diabetes to see if the its benefits extend its influence beyond hypoglycemia warning signs. Using continuous glucose sensing technology and simultaneous assessment of autonomic function with Holter monitoring, the investigators studied the effect of caffeine vs. placebo in 19 patients long-standing type 1 diabetes Mean duration of nocturnal hypoglycemia was 49 minutes with caffeine and 132 minutes with placebo. This reduction in duration of night time hypoglycemia seen with caffeine was due to a decline in the number of episodes of moderate hypoglycemia at the expense of mild hypoglycemic episodes. Overall, there was no correlation between reduced heart rate variability, a marker of autonomic dysfunction, and hypoglycemic events.
Our last headline is a sad one because it shows that type 2 diabetics in the US are failing to control their blood glucose levels. The goal of the hemoglobin A1c test is 6.5 percent however the American Association of Clinical Endocrinologists survey of 157,000 patients in 2003 and 2004 showed that two thirds were not meeting this goal. Research has shown that every 1 percent increase above 6 percent elevates a diabetic’s risk for serious complications of the disease.
Headlines are over and now we begin our abstracts. Our first from the Archives of Internal Medicine, 2005;165:997-1003 is titled Dairy consumption and risk of type 2 diabetes mellitus in men by Hyon K. Choi, MD, DrPH et al. Diet and lifestyle modifications can substantially reduce the risk of type 2 diabetes. Although 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. To that end, the researchers prospectively examined the relation between dairy intake and incident cases of type 2 diabetes in 41, 254 male participants with no history of diabetes, cardiovascular disease, and cancer at baseline in the health Professionals Follow-up Study. During the 12 years of follow-up, they documented 1243 incident cases of type 2 diabetes. Dairy intake was associated with a modestly lower risk of type 2 diabetes. After adjusting for potential confounders, including body mass index, physical activity, and dietary factors, the relative risk for type 2 diabetes in men in the top quintile of dairy intake was 0.77 compared with those in the lowest quintile. Each serving-per-day increase in total intake was associated with a 9% lower risk for type 2 diabetes. The corresponding relative risk was 0.88 for low-fat dairy intake and 0.99 for high-fat dairy intake. The association did not vary significantly according to body mass index. The researchers concluded that dietary patterns characterized by higher dairy intake, especially low-fat dairy intake, may lower the risk for type 2 diabetes in men.
Diabetes Care 28:1339-1345, 2005 has a article of interest to those of you who write in about depression and diabetes titled Depression and all-cause and coronary heart disease mortality among adults with and without diabetes by Leonard E. Egede, MD, MS et al. The aim of this study was to evaluate the effect of depression on all-cause and coronary heart disease mortality among adults with and without diabetes. They studied 10.025 participants in the population-based National health and Nutrition Examination Survey Epidemiologic Follow-up Study who were alive and interviewed in 1982 and had complete data for the Center for Epidemiologic Studies Depression Scale. Four groups were created based on diabetes and depression status in 1982:1)no diabetes, no depression (reference groups); 2) no diabetes, depression present; 3) diabetes present, no depression; and 4) diabetes present, depression present. Cox proportional hazards regression models were used to calculate multivariate-adjusted hazard ratios (HRs) of death for each group compared with the reference group. Over 8 years (83,624 person-years of follow-up), 1925 deaths were documented, including 522 deaths from CHD. Mortality rate per 1,000 person-years of follow-up was the highest in the group with both diabetes and depression. Compared with the reference group, HRs for all-cause mortality were no diabetes, depression patients present, 1.20; diabetes present, no depression 1.88; and diabetes present, depression present, 2.50. HRs for CHD mortality were no diabetes, depression present, 1.29; diabetes present, no depression 2.26; and diabetes present, depression present, 2.43. They concluded that the coexistence of diabetes and depression is associated with a significantly increased risk of death from all causes, beyond that due to having either diabetes or depressions alone.
Diabetes Care 28:1358-1365, 2005 has an new article that caught our eye titled Islet transplantation is associated with an improvement of cardiovascular function in type 1 diabetic kidney patients by Paolo Fiorina, MD et al. Cardiovascular mortality and morbidity are major problems in type 1 diabetes patients with end-stage renal disease (ESRD). This study tried to determine whether islet transplantation can improve cardiovascular function in these patients. The researchers assessed various markers of cardiac function at baseline and 3 years later in a population of 42 type 1 diabetic patients with ESRD who received a kidney transplant. Seventeen patients then received an islet transplant that had persistent function as defined by long-term C-peptide secretion (kidney-islet group). Twenty-five patients did not receive a functioning islet transplant (kidney-only group). GHb levels were similar in the two groups, whereas the exogenous insulin requirement was lower in the kidney-islet group with persistent C-peptide secretion. Over-all, cardiovascular parameters improved n the kidney-islet group, but not in the kidney-only group, with improvement of ejection fraction and peak filling rate in end-diastolic volume per second. Time to peak filling rate remained stable in the kidney-islet group but worsened in the kidney-only group. The kidney-islet group also showed a reduction of both QT dispersion with higher erthrocytes NA+ -K+ -ATPAse activity. In the kidney-islet group only, both atrial stabilization of intima-media thickness. The researchers concluded that the study showed that type 1 diabetic ESRD patients receiving a kidney transplant and functioning islet transplant showed an improvement of cardiovascular function for up to 3 years of follow-up compared with the kidney-only group, who experienced an early failure of the islet graft or did not receive an islet graft.
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