Eye Outcomes in Veteran Affairs Diabetes Trial (VADT) After 17 Years.

OBJECTIVE: The objective of this study was to assess the long-term role of intensive glycemic control (INT) compared with standard glycemic control in accumulated eye procedures in patients with advanced diabetes. RESEARCH DESIGN AND METHODS: We compared the effect of treatment assignment on the accumulated number of eye procedures during the intervention period of the Veteran Affairs Diabetes Trial (VADT) (2000-2008) (median follow-up 5.6 years), the interim VADT follow-up study (2000-2013), and the full 17 years of VADT follow-up (2000-2017). We further analyzed data using various cardiovascular markers in two models. Model I included total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, systolic and diastolic blood pressure, and BMI. Model II included these covariates plus age and diabetic retinopathy (DR) severity score at baseline of the original trial. RESULTS: The final analysis of the data showed a mild but nonsignificant increase in number of procedures and in retinal or retinal plus cataract surgery during the three periods of the study. CONCLUSIONS: We found no significant benefit of INT during the original trial period in eye-related procedures, such as various procedures for DR, or during the 17 years of follow-up in cataract surgery. However, after adjusting data for some known vascular markers, the increase in the number of eye procedures with INT becomes more prevalent. This finding indicates that INT might not have a protective role in events requiring surgery in individuals with advanced diabetes.

BIOTIN INTERFERENCE WITH ROUTINE CLINICAL IMMUNOASSAYS: UNDERSTAND THE CAUSES AND MITIGATE THE RISKS.

OBJECTIVE: The objectives of this report are to review the mechanisms of biotin interference with streptavidin/biotin-based immunoassays, identify automated immunoassay systems vulnerable to biotin interference, describe how to estimate and minimize the risk of biotin interference in vulnerable assays, and review the literature pertaining to biotin interference in endocrine function tests. METHODS: The data in the manufacturer's "Instructions for Use" for each of the methods utilized by seven immunoassay system were evaluated. We also conducted a systematic search of PubMed/MEDLINE for articles containing terms associated with biotin interference. Available original reports and case series were reviewed. Abstracts from recent scientific meetings were also identified and reviewed. RESULTS: The recent, marked, increase in the use of over-the-counter, high-dose biotin supplements has been accompanied by a steady increase in the number of reports of analytical interference by exogenous biotin in the immunoassays used to evaluate endocrine function. Since immunoassay methods of similar design are also used for the diagnosis and management of anemia, malignancies, autoimmune and infectious diseases, cardiac damage, etc., biotin-related analytical interference is a problem that touches every area of internal medicine. CONCLUSION: It is important for healthcare personnel to become more aware of immunoassay methods that are vulnerable to biotin interference and to consider biotin supplements as potential sources of falsely increased or decreased test results, especially in cases where a lab result does not correlate with the clinical scenario. ABBREVIATIONS: FDA = U.S. Food & Drug Administration FT3 = free tri-iodothyronine FT4 = free thyroxine IFUs = instructions for use LH = luteinizing hormone PTH = parathyroid hormone SA/B = streptavidin/biotin TFT = thyroid function test TSH = thyroid-stimulating hormone.

Observation on renal outcomes in the Veterans Affairs Diabetes Trial.

OBJECTIVE: The Veterans Affairs Diabetes Trial (VADT) was a randomized, prospective, controlled trial of 1,791 patients with type 2 diabetes to determine whether intensive glycemic control would reduce cardiovascular events compared with standard control. The effect of intensive glycemic control and selected baseline variables on renal outcomes is reported. RESEARCH DESIGN AND METHODS: Baseline mean age was 60.4 years, mean duration of diabetes was 11.5 years, HbA(1c) was 9.4%, and blood pressure was 132/76 mmHg. The renal exclusion was serum creatinine >1.6 mg/dL. Renal outcomes were sustained worsening of the urine albumin-to-creatinine ratio (ACR) and sustained worsening by one or more stages in the estimated glomerular filtration rate (eGFR). RESULTS: Intensive glycemic control did not independently reduce ACR progression but was associated with a significant attenuation in the progression of ACR in those who had baseline photocoagulation, cataract surgery, or both. The beneficial effect of intensive glycemic control increased with increasing BMI and with decreasing diastolic blood pressure (DBP). Intensive glycemic control was associated with less worsening of eGFR with increasing baseline ACR and insulin use. Baseline systolic blood pressure, triglycerides, and photocoagulation were associated with worsening of eGFR. CONCLUSIONS: Intensive glycemic control had no significant effect on the progression of renal disease in the whole cohort but was associated with some protection against increasing ACR in those with more advanced microvascular disease, lower baseline DBP, or higher baseline BMI and on worsening of eGFR in those with high baseline ACR.

Profiling of heparin-induced thrombocytopenia antibody levels in patients with and without diabetes.

Heparin/platelet factor 4 (H:PF4) antibodies are the causative agent in heparin-induced thrombocytopenia (HIT). The antibodies are frequently formed after exposure to heparin, most commonly without any signs of clinical HIT. Heparin-induced thrombocytopenia antibodies have been detected by enzyme-linked immunosorbent assay (ELISA) in individuals who have not been exposed to heparin. It is possible that the antibodies could be elicited by PF4 associated with endogenous, heparin-like glycosaminoglycans (GAGs). This risk would be higher in individuals with endothelial dysfunction and chronic platelet activation. In the setting of an outpatient endocrinology clinic, both diabetic and nondiabetic patients were studied and compared with healthy volunteers. Heparin/platelet factor 4 antibody titers were measured by ELISA and analyzed to determine the frequency of clinically seropositive responses, and median and interquartile ranges of baseline antibody titers. The study found no increase in frequency of ELISA-positive patients among diabetic patients. Moreover, the diabetic population had lower overall level of H:PF4 antibody titer, especially the subgroups treated with thiazolidinedione drugs or angiotensin receptor blockers. Further studies are needed to determine whether subthreshold titers of HIT antibody may be reflective of the physiological state of platelet/endothelial balance.

Ethnicity, race, and clinically significant macular edema in the Veterans Affairs Diabetes Trial (VADT).

OBJECTIVE: To determine risk factors in clinically significant macular edema (CSME) and if increased CSME in minorities is due to ethnicity or other factors in the Veterans Affairs Diabetes Trial (VADT). METHODS: CSME prevalence based on 7-field stereo fundus photographs in 1268 patients with type 2 diabetes was related to ethnicity, demographics and biochemistries by univariate and multivariate analyses. RESULTS: Hispanics (H) made up 17.5% and African Americans (AA) 17.7% of the cohort. CSME prevalence was 10%. In univariate analysis, CSME was more prevalent in H, 18%, and AA, 15.6% than in non-Hispanic Whites (NHW), 6.3%, p<0.01. Univariate regression of CSME associated with younger age, younger onset of diabetes; longer duration; retinopathy severity; and high HbA1c, BP, urine albumin/creatinine, and amputation, all p<0.01. In multivariate regression, CSME was associated with ethnicity/race (Hispanic White vs. non-Hispanic White, OR, (95% CI), 2.30, (1.35-3.92), p<0.01; African American vs. non-Hispanic White, 2.30, (1.33-4.00), p<0.01), diastolic BP (1.13 per 5 mm Hg, (1.02-1.23), p=0.03), amputation (3.0, (1.11-8.13), p=0.04), and retinopathy severity ( approximately 30, ( approximately 17 to approximately 59), p<0.01). CONCLUSION: The prevalence of CSME in the VADT is associated with ethnicity as well as diastolic BP, amputation, and retinopathy severity.

Intensive glucose-lowering therapy reduces cardiovascular disease events in veterans affairs diabetes trial participants with lower calcified coronary atherosclerosis.

OBJECTIVE: This study investigated the hypothesis that baseline calcified coronary atherosclerosis may determine cardiovascular disease events in response to intensive glycemic control within the Veterans Affairs Diabetes Trial (VADT). RESEARCH DESIGN AND METHODS: At baseline, 301 type 2 diabetic participants in the VADT, a randomized trial comparing the effects of intensive versus standard glucose lowering on cardiovascular events, had baseline coronary atherosclerosis assessed by coronary artery calcium (CAC) measured by computed tomography. Participants were followed over the 7.5-year study for development of cardiovascular end points. RESULTS: During a median follow-up duration of 5.2 years, 89 cardiovascular events occurred. Although intensive glucose-lowering therapy did not significantly reduce cardiovascular events in the substudy cohort as a whole, there was evidence that the response was modified by baseline CAC, as indicated by significant P values for treatment by log(CAC + 1) interaction terms in unadjusted and multivariable-adjusted models (0.01 and 0.03, respectively). Multivariable-adjusted hazard ratios (HRs) for the effect of treatment indicated a progressive diminution of benefit with increasing CAC. Subgroup analyses were also conducted for clinically relevant CAC categories: those above and below an Agatston score of 100. Among those randomized to intensive treatment, for the subgroup with CAC >100, 11 of 62 individuals had events, while only 1 of 52 individuals with CAC < or = 100 had an event. The multivariable HR for intensive treatment for those with CAC >100 was 0.74 (95% CI 0.46-1.20; P = 0.21), while for the subgroup with CAC < or = 100, the corresponding HR was 0.08 (0.008-0.77; P = 0.03), with event rates of 39 and 4 per 1,000 person-years, respectively. CONCLUSIONS: These data indicate that intensive glucose lowering reduces cardiovascular events in those with less extensive calcified coronary atherosclerosis.

Glucose control and vascular complications in veterans with type 2 diabetes.

BACKGROUND: The effects of intensive glucose control on cardiovascular events in patients with long-standing type 2 diabetes mellitus remain uncertain. METHODS: We randomly assigned 1791 military veterans (mean age, 60.4 years) who had a suboptimal response to therapy for type 2 diabetes to receive either intensive or standard glucose control. Other cardiovascular risk factors were treated uniformly. The mean number of years since the diagnosis of diabetes was 11.5, and 40% of the patients had already had a cardiovascular event. The goal in the intensive-therapy group was an absolute reduction of 1.5 percentage points in the glycated hemoglobin level, as compared with the standard-therapy group. The primary outcome was the time from randomization to the first occurrence of a major cardiovascular event, a composite of myocardial infarction, stroke, death from cardiovascular causes, congestive heart failure, surgery for vascular disease, inoperable coronary disease, and amputation for ischemic gangrene. RESULTS: The median follow-up was 5.6 years. Median glycated hemoglobin levels were 8.4% in the standard-therapy group and 6.9% in the intensive-therapy group. The primary outcome occurred in 264 patients in the standard-therapy group and 235 patients in the intensive-therapy group (hazard ratio in the intensive-therapy group, 0.88; 95% confidence interval [CI], 0.74 to 1.05; P=0.14). There was no significant difference between the two groups in any component of the primary outcome or in the rate of death from any cause (hazard ratio, 1.07; 95% CI, 0.81 to 1.42; P=0.62). No differences between the two groups were observed for microvascular complications. The rates of adverse events, predominantly hypoglycemia, were 17.6% in the standard-therapy group and 24.1% in the intensive-therapy group. CONCLUSIONS: Intensive glucose control in patients with poorly controlled type 2 diabetes had no significant effect on the rates of major cardiovascular events, death, or microvascular complications with the exception of progression of albuminuria (P = 0.01) [added]. (ClinicalTrials.gov number, NCT00032487.)

Comparison of dilated fundus examinations with seven-field stereo fundus photographs in the Veterans Affairs Diabetes Trial.

OBJECTIVE: The Veterans Affairs Diabetes Trial (VADT) is a 20-medical center, prospective, randomized study of 1792 Type 2 diabetic individuals primarily aimed at determining whether intensive glycemic control prevents macrovascular events. We report a comparison of fundus photographs and ophthalmologic examination at baseline, permitting an evaluation of multiple settings similar to common clinical practice. RESEARCH DESIGN AND METHODS: A 340-patient subset had both local dilated fundus examinations and centrally read seven-field stereo fundus photographs completed within 60 days of each other (median 28 days). Local examiners were unaware of the stereo photographs. RESULTS: Overall, agreement within one step was 76% and exact agreement between ophthalmoscopy and central gradings of fundus photographs on a five-step retinopathy severity scale was 43% (weighted kappa 0.42, CI 0.35-0.48). In about 90% of disagreements the severity level was higher by photographic grading. The sensitivity for ophthalmoscopy compared to grading of fundus photographs for the detection of any retinopathy was 51% and specificity was 91%. For proliferative diabetic retinopathy (PDR), sensitivity was 61% and specificity 98%. Only one eye was high-risk PDR, and it was detected by both methods. For clinically significant macular edema, these measures were 24% and 98%, respectively. The disagreements were of possible clinical importance in three cases (<1%). CONCLUSION: Most disagreements occurred in eyes rated near the milder end of a category and/or resulted from small differences between the ophthalmoscopic and photographic definitions used in classifying severity. There were reasonably few disagreements of possible clinical significance.

Profound effects of burn and ethanol on proinflammatory cytokines of the reproductive axis in the male mouse.

Thermal injury is often associated with previous ethanol exposure, and close to 50% of patients admitted to a burn unit have a potentially high blood ethanol level. Cellular mechanisms by which ethanol and/or burn affect the hypothalamic-pituitary-gonadal (HPG) axis are not entirely understood. However, it is known that the proinflammatory cytokines, tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 influence negatively on the endocrine functions of the HPG. We report a time course study (6, 12, 24, and 48 hours) of the effects of ethanol, burn, or the combination of burn/ethanol on proinflammatory cytokines of the hypothalamus, pituitary and testes of male C57Bl/6 mice. We found that there were highly significant increases in each of these cytokines caused by ethanol, burn, and burn/ethanol compared with sham/vehicle (P < .001). This was true in hypothalamus, pituitary, and testes. Because these cytokines generally reduce reproductive function, it may be that proinflammatory cytokines of HPG axis mediate the deleterious effects of burn and/or ethanol on mammalian reproduction.

Effects of chronic ethanol (EtOH) administration on pro-inflammatory cytokines of the hypothalamic-pituitary-gonadal (HPG) axis in female rats.

We and others have investigated the effects of acute and chronic ethanol (EtOH) administration on function of the hypothalamic-pituitary-gonadal (HPG) axis in female rats, consistently finding EtOH to be detrimental. There are now substantial data that pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6), have anti-reproductive effects. If EtOH increased levels of these cytokines, such data would be consistent with, though not necessarily prove, a cytokine mediated mechanism for EtOH's deleterious effects on reproduction. Young adult female Sprague Dawley rats were used. In the experiment reported here, the Lieber DeCarli diet was used, with animals fed a 36% EtOH containing diet or pair fed an identical diet which contained dextrimaltose instead of EtOH. This was done for 4 to 6 weeks. TNFalpha and IL-6 were measured in the hypothalamus, pituitary, and ovary by ELISA. EtOH exposure resulted in significant increases in TNFalpha and IL-6 in hypothalami, pituitaries, and ovaries. The data reported here are the first to show consistent stimulatory effects of EtOH exposure on cytokines in the reproductive axis of female rats. Because the effects of these cytokines are generally anti-reproductive, these data provide a rational for more rigorous testing of the notion that part of EtOH's deleterious HPG effects may be due to such immuno-endocrine interactions.

Ethnicity, race, and baseline retinopathy correlates in the veterans affairs diabetes trial.

OBJECTIVE: The Veterans Affairs Diabetes Trial (VADT) cohort is enriched with approximately 20% Hispanics and 20% African Americans, affording a unique opportunity to study ethnic differences in retinopathy. RESEARCH DESIGN AND METHODS: Cross-sectional analyses on the baseline seven-field stereo fundus photos of 1,283 patients are reported here. Diabetic retinopathy scores are grouped into four classes of increasing severity: none (10-14), minimal nonproliferative diabetic retinopathy (NPDR) (15-39), moderate to severe NPDR (40-59), and proliferative diabetic retinopathy (60+). These four groups have also been dichotomized to none or minimal (10-39) and moderate to severe diabetic retinopathy (40+). RESULTS: The prevalence of diabetic retinopathy scores >40 was higher for Hispanics (36%) and African Americans (29%) than for non-Hispanic whites (22%). The difference between Hispanics and non-Hispanic whites was significant (P < 0.05). Similarly, the prevalence of diabetic retinopathy scores >40 was significantly higher in African Americans than in non-Hispanic whites (P < 0.05). These differences could not be accounted for by an imbalance in traditional risk factors such as age, duration of diagnosed diabetes, HbA(1c) (A1C), and blood pressure. Diabetic retinopathy severity scores were also significantly associated with increasing years of disease duration, A1C, systolic and diastolic blood pressure, the degree of microalbuminuria, fibrinogen, and the percentage of patients with amputations. There was no relationship between retinopathy severity and the percentage of people who had strokes or cardiac revascularization procedures. There was an inverse relationship between retinopathy severity and total cholesterol, triglycerides, and plasminogen activator inhibitor-1 as well as with smoking history. Diabetic retinopathy scores were not associated with age. CONCLUSIONS: In addition to many well-known associations with retinopathy, a higher frequency of severe diabetic retinopathy was found in the Hispanic and African-American patients at entry into the VADT that is not accounted for by traditional risk factors for diabetic retinopathy, and these substantial ethnic differences remain to be explained.

Ethanol-induced alterations in Rab proteins: possible implications for pituitary dysfunction.

Chronic exposure of pubertal male rats to ethanol results in a decline in serum testosterone, increased gonadotropins, pituitary luteinizing hormone (LH) and follicle stimulating hormone (FSH) content, and decreased or inappropriately normal serum LH and FSH levels, suggesting impaired secretory release of gonadotropins. The molecular mechanisms behind this disorder are undefined, but a disruption of vesicle-mediated secretory processes is possible because intracellular protein trafficking pathways are involved in secretion of glycoproteins such as FSH and LH. Because small GTP-binding proteins of Rab family have been implicated as key regulators of membrane and protein trafficking in mammalian cells, this study was designed to test if ethanol-impaired pituitary FSH and LH secretion is associated with changes in Rab proteins, particularly Rab1B, Rab3B, Rab6, and Rab11. Male Sprague-Dawley rats 35 days old were pair-fed a Lieber-DeCarli diet with ethanol or without ethanol for 5 to 60 days. After ethanol exposure, serum testosterone levels decreased while LH and FSH were inappropriately unchanged. Immunohistochemical staining showed decreased Rab1B, Rab3B, and Rab11 protein levels in ethanol-treated pituitaries. Immunoblotting showed that ethanol induced a transient reduction in Rab6 after 5 days of ethanol exposure, whereas Rab3B decreased after 20 days, Rab11 after 30 days, and Rab1B after 60 days. Despite these changes in Rab proteins, mRNA levels were unaffected by ethanol exposure. We concluded that reductions in key Rab proteins may lead to altered vesicle trafficking and may play a role in disruption of pituitary FSH and LH secretion caused by ethanol.

Hepatic apoptosis and proliferation in male and female rats fed alcohol: role of cytokines.

BACKGROUND: The female liver is more sensitive to the toxic effect of chronic alcohol intake than the male liver. The aim of the study was to compare the influence of gender and sex hormonal status on apoptosis and cell proliferation following chronic ethanol intake. METHODS: Male and female rats were pair fed for 8 weeks a liquid diet containing 36% of their total daily calories as ethanol (ETOH group) or sucrose (control group). Liver samples were analyzed for apoptosis and hepatocyte proliferation by immunohistochemistry. The hepatic production of factors able to influence cell death and proliferation, such as tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6) were determined. RESULTS: In both male and female rats, ethanol intake promoted apoptosis in the liver. This effect of ethanol was more evident in female than male rat livers. Hepatic TNFalpha levels, which promote apoptosis, are significantly more elevated in female than in male livers. Hepatic IL-6 production, which promotes hepatocyte proliferation, was induced by ethanol only in males, but not female animals. CONCLUSION: This observed difference in cytokine responses may contribute to the enhanced sensitivity of female liver to EtOH-induced injury.

EtOH disrupts female mammalian puberty: age and opiate dependence.

The major drug of abuse among teenagers in the United States continues to be ethanol (EtOH), but use is seen in children as young as nine. In the studies reported here, the impact of EtOH on biologic and hormonal parameters of puberty was assessed in female rats. Rats were fed a liquid diet containing EtOH, pair fed an identical liquid diet containing dextrimaltose instead of EtOH, or fed a liquid diet not containing EtOH ad libitum. Feeding was started at 21, 25, or 28 d of age. EtOH markedly delayed the age at vaginal opening (34.5 +/- 0.5 d in controls vs 48.5 +/- 2.4 d in EtOH animals; p < 0.001), delayed the age at first estrous (40.9 +/- 0.6 d in controls vs 61.2 +/- 2.6 d in EtOH animals; p < 0.001), increased the length of the estrous cycle, and decreased the number of proestrous days. EtOH, concomitant with reduced ovarian and uterine weight, decreased serum estradiol and progesterone. Associated with these changes in ovarian hormones there was a selective increase in follicle-stimulating hormone, but not luteinizing hormone. EtOH consistently reduced insulin-like growth factor-1. In general, EtOH-induced disruption was more severe the younger the animals were at the start of feeding. Opiate receptor blockade with naltrexone completely prevented the EtOH-induced delay in vaginal opening. The impact of EtOH on female puberty is dramatic, is an emerging public health problem, and deserves more study.