Abdullah Taslipinar

Endogenous Testosterone, Endothelial Dysfunction, and Cardiovascular Events in Men with Nondialysis Chronic Kidney Disease

BACKGROUND AND OBJECTIVES Deterioration of kidney function impairs testosterone production, with hypogonadism being common in men with chronic kidney disease (CKD). In nonrenal populations, testosterone is suggested to participate in the atherosclerotic process. In male dialysis patients, we showed that low testosterone increases the risk of mortality. We here studied plausible links among testosterone levels, vascular derangements, and cardiovascular events in nondialysis CKD men. DESIGN, SETTING, PARTICIPANTS, & METHODS This was a cross-sectional analysis in which flow-mediated dilation (FMD) was assessed in 239 CKD male patients (stages 1 to 5; mean age 52 ± 12 years), together with routine measurements, serum total and free testosterone, and follow-up for cardiovascular outcomes. RESULTS Total and free testosterone levels decreased in parallel with the reduction of kidney function. Multiple regression analyses showed that total and free testosterone significantly and independently contributed to explain the variance of FMD. After a median follow-up of 31 months (range 8 to 35 months), 22 fatal and 50 nonfatal cardiovascular events occurred. In Cox analysis, the risk of cardiovascular events was reduced by 22% for each nanomole-per-liter increment of total testosterone. This reduced risk persisted after adjustment for age, renal function, diabetes mellitus, previous cardiovascular history, C-reactive protein, albumin, and FMD. The same was true for free testosterone concentrations. CONCLUSIONS The reduction in endogenous testosterone levels observed with progressive CKD was inversely associated with endothelial dysfunction and exacerbated the risk of future cardiovascular events in nondialysis male CKD patients.

Prolactin Levels, Endothelial Dysfunction, and the Risk of Cardiovascular Events and Mortality in Patients with CKD

BACKGROUND AND OBJECTIVES Both prolactin clearance and production are altered in CKD. In nonrenal populations, emerging evidence suggests that prolactin participates in the atherosclerotic process. Given the elevated cardiovascular risk of CKD, this study examined links between prolactinemia, vascular derangements, and outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This observational study was conducted in two cohorts: one with 457 nondialyzed CKD patients (mean age 52±12 years; 229 men) with measurements of flow-mediated dilation (FMD) and carotid intima-media thickness and one with 173 hemodialysis patients (65±12 years; 111 men) with measurements of pulse wave velocity (PWV). Patients were followed for cardiovascular events (n=146, nondialyzed cohort) or death (n=79, hemodialysis cohort). RESULTS Prolactin levels increased along with reduced kidney function. Prolactin significantly and independently contributed to explain the variance of both FMD (in nondialyzed patients) and PWV (in hemodialysis patients), but not intima-media thickness. In Cox analyses, the risk of cardiovascular events in nondialyzed patients increased by 27% (hazard ratio [HR], 1.27; 95% confidence interval [95% CI], 1.17-1.38) for each 10 ng/ml increment of prolactin. Similarly, the risk for all-cause and cardiovascular mortality in hemodialysis patients increased by 12% (HR, 1.12; 95% CI, 1.06-1.17) and 15% (HR, 1.15; 95% CI, 1.08-1.21), respectively. This was true after multivariate adjustment for confounders and after adjustment within the purported causal pathway (FMD or PWV). CONCLUSIONS Prolactin levels directly associated with endothelial dysfunction/stiffness and with increased risk of cardiovascular events and mortality in two independent cohorts of CKD patients.

Complementary and alternative medicine use among Turkish diabetes patients

OBJECTIVES To measure the frequency of complementary and alternative medicine (CAM) use among patients with diabetes mellitus, to determine demographic characteristics making it more likely to using CAM, and to find out how benefits, if any, were perceived by patients. DESIGN A 24-item survey questionnaire administered to 371 return patients with diabetes mellitus. SETTING Outpatient clinic of the Department of Endocrinology and Metabolism department of Gülhane Military Medical Academy, Ankara, Turkey. MAIN OUTCOME MEASURES Questionnaire-based measures of demographics, motives, expectations, and effects of using CAM, and types and reported perceived benefits of CAM practiced on patients with diabetes mellitus. RESULTS Forty-one percent of patients (n=152) used at least one of CAM practices; and age, birthplace, educational status, duration of diabetes and family type were significant factors in such behaviour. CONCLUSIONS Patients born in cities, having more education and longer duration of diabetes, at relatively young ages and living in large families were more likely to use CAM. More than half of those using CAM (n=80, 52.7%) reported as benefits the feelings of either strengthening of body, or being in good psychological condition, or disappearance of several symptoms.

The relationship between inflammation, endothelial dysfunction and proteinuria in patients with diabetic nephropathy.

Abstract Objectives. Diabetic nephropathy (DN) is a major manifestation of microangiopathy in patients with Diabetes Mellitus (DM). Inflammation is one of the major factors in the formation of endothelial dysfunction. Endothelial dysfunction is a major contributor to the complications of DM. The aim of the present study was to investigate the possible relationship between inflammation, endothelial dysfunction and proteinuria in patients with diabetic nephropathy. Materials and methods. Plasma TNF-α and IL-6, pro-inflammatory cytokines, concentrations were measured in 25 patients with DN and in 30 diabetic control subjects. Also, we evaluated the markers of endothelial dysfunction such as flow mediated dilatation (FMD), nitrate-mediated dilatation (NMD) and carotid intima-media thickness (CIMT). Results. TNF-α, IL-6 and high-sensitivity C-reactive protein concentrations were significantly higher (p = 0.012, p = 0.006 and p < 0.001, respectively) in the patients with DN than the controls. And, urinary protein concentrations were significantly higher (p < 0.001) but eGFR levels were significantly lower (p < 0.001) in the patients with DN. FMD was significantly lower in DN patients (p < 0.001). We have observed that FMD correlated negatively with body mass index (r = −0.424, p < 0.05). And there was also a positive correlation between TNF-α and urinary protein concentrations in the patients with DN (p < 0.05). Conclusion. TNF-α, IL-6, hsCRP and urinary protein concentrations are higher in the DN patients. There were no correlations among pro-inflammatory cytokines concentrations and markers of vascular endotelial disfunction. These findings did not show vascular endothelial dysfunction, but may indicate glomerular endothelial dysfunction.

Metabolic syndrome and the effect of testosterone treatment in young men with congenital hypogonadotropic hypogonadism

OBJECTIVE The relationship between metabolic syndrome (MS) and hypogonadism has always been investigated in study groups confounded with aging, obesity or chronic metabolic disorders. So far, there has been no data about the presence of MS in young hypogonadal patients. Also, there is controversial data about the metabolic effects of testosterone replacement therapy. We investigated the frequency of MS in treatment-naïve, young men with congenital hypogonadal hypogonadism (CHH). We also searched for the effect of testosterone replacement on the metabolic profiles of this specific patient group. DESIGN Retrospective analysis. METHODS A total of 332 patients (age 21.68 ± 2.09 years) were enrolled. The control group included 395 age- and body mass index (BMI)-matched healthy young men (age 21.39 ± 1.49 years). Standard regimen of testosterone esters (250 mg/3 weeks) was given to 208 patients. RESULTS MS was more prevalent in CHH (P<0.001) according to healthy controls. The patients had higher arterial blood pressure, waist circumference (WC), triglyceride (P<0.001 for all), fasting glucose (P=0.02), fasting insulin (P=0.004), homeostatic model assessment of insulin resistance (HOMA-IR) (P=0.002) and lower high density lipoprotein (HDL) cholesterol (P<0.001) levels. After 5.63±2.6 months of testosterone treatment, the BMI, WC (P<0.001 for both), systolic blood pressure (P=0.002) and triglyceride level (P=0.04) were increased and the total and HDL cholesterol levels were decreased (P=0.02 and P<0.001 respectively). CONCLUSIONS This study shows increased prevalence of MS and unfavorable effects of testosterone replacement in young patients with CHH. Long-term follow-up studies are warranted to investigate the cardiovascular safety of testosterone treatment in this specific population.

High plasma level of long Pentraxin 3 is associated with insulin resistance in women with polycystic ovary syndrome

Objectives: Polycystic ovary syndrome (PCOS) is characterized by insulin resistance. Chronic low-grade inflammation has been anticipated to play role in the pathogenesis of both insulin resistance and atherosclerosis. Pentraxin 3 (PTX3) is an inflammatory mediator synthesized in a variety of cells and tissues including heart, vascular endothelial cells, macrophages and adipocytes. In the present study, serum PTX3 level and its relationship with insulin resistance were investigated in patients with PCOS. Materials and Methods: Forty patients with PCOS and 40 age- and body mass index (BMI)-matched healthy controls were enrolled in the study. PTX3 and high-sensitivity C-reactive protein (hs-CRP) levels were determined by enzyme immunoassay (EIA). Insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) formula. Results: Plasma levels of PTX3, hs-CRP and HOMA-IR scores were all significantly higher (p = 0.021, p = 0.002 and p = 0.0001, respectively) in women with PCOS compared with healthy controls. Blood PTX3 level correlated positively with hs-CRP, BMI, waist-to-hip ratio (WHR), HOMA-IR and negatively with high-density lipoprotein cholesterol level (p < 0.05, for all). After adjustment for age and BMI, PTX3, total testosterone levels and BMI remained as independent predictors of HOMA-IR scores (p < 0.05, for all). Conclusion: PTX3 level is increased in patients with PCOS in concordance with insulin resistance.

The Accuracy of Home Glucose Meters in Hypoglycemia

BACKGROUND Home glucose meters (HGMs) may not be accurate enough to sense hypoglycemia. We evaluated the accuracy and the capillary and venous comparability of five different HGMs (Optium Xceed [Abbott Diabetes Care, Alameda, CA, USA], Contour TS [Bayer Diabetes Care, Basel, Switzerland], Accu-Chek Go [Roche Ltd., Basel, Switzerland], OneTouch Select [Lifescan, Milpitas, CA, USA], and EZ Smart [Tyson Bioresearch Inc., Chu-Nan, Taiwan]) in an adult population. METHODS The insulin hypoglycemia test was performed to 59 subjects (56 males; 23.6 +/- 3.2 years old). Glucose was measured from forearm venous blood and finger capillary samples both before and after regular insulin (0.1 U/kg) was injected. Venous samples were analyzed in the reference laboratory by the hexokinase method. In vitro tests for method comparison and precision analyses were also performed by spiking the glucose-depleted venous blood. RESULTS All HGMs failed to sense hypoglycemia to some extend. EZ Smart was significantly inferior in critical error Zone D, and OneTouch Select was significantly inferior in the clinically unimportant error Zone B. Accu-Chek Go, Optium Xceed, and Contour TS had similar performances and were significantly better than the other two HGMs according to error grid analysis or International Organization for Standardization criteria. The in vitro tests were consistent with the above clinical data. The capillary and venous consistencies of Accu-Chek Go and OneTouch Select were better than the other HGMs. CONCLUSIONS The present results show that not all the HGMs are accurate enough in low blood glucose levels. The patients and the caregivers should be aware of these restrictions of the HGMs and give more credit to the symptoms of hypoglycemia than the values obtained by the HGMs. Finally, these results indicate that there is a need for the revision of the accuracy standards of HGMs in low blood glucose levels.

Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy.

OBJECTIVE Small myelinated (A-delta) and unmyelinated (C) somatic sensory fibers are initially affected and may be the earliest exhibited sign of neuropathy in glucose dysmetabolism. Cutaneous silent period (CSP) is an inhibitory spinal reflex and its afferents consist of A-delta nerve fibers. The aim of this study was to evaluate CSP changes in Type 2 diabetic patients with small fiber neuropathy. METHODS Forty-three patients and 41 healthy volunteers were included. CSP latency and duration, as well as CSP latency difference of the upper and lower extremities, were examined. RESULTS Nerve conduction studies were within normal limits in both groups. Lower extremity CSP latency was longer (122.1+/-15.5 vs. 96.4+/-6.4 ms; p<0.001), CSP duration was shorter (29.5+/-8.9 vs. 43.1+/-5.0 ms; p<0.001), and latency difference was longer (48.1+/-12.6 vs. 22.7+/-3.7; p<0.001) in patients than controls. The difference was more significant in patients with neuropathic pain. No significant difference existed in upper extremity on CSP evaluation. CONCLUSION The CSP evaluation together with nerve conduction study, has been demonstrated to be beneficial and performance of latency difference in addition to CSP latency and duration may be a valuable parameter in electrophysiological assessment of diabetic patients with small fiber neuropathy. SIGNIFICANCE An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information.

Effects of three different medications on metabolic parameters and testicular volume in patients with hypogonadotropic hypogonadism: 3‐year experience

The aim of this study was to demonstrate the influences of three different treatment strategies on biochemical parameters and testicular volume (TV) in patients with idiopathic hypogonadotropic hypogonadism (IHH).

Osteoprotegerin, Fibroblast Growth Factor 23, and Vitamin D3 Levels in Male Patients with Hypogonadism

Cardiometabolic disorders and osteoporosis are prevalent in patients with hypogonadism. Osteoprotegerin (OPG) and fibroblast growth factor-23 (FGF-23), are co-secreted from bones and vascular endothelium, regulating bone mineral metabolism and vascular functions. Vitamin D is another hormone with dual effects on bone and vascular metabolism. The aim of this study was to search for any difference between the serum levels of OPG, FGF-23, and vitamin D in patients with hypogonadism and the healthy controls. We also aimed to search for any relationship between these parameters and endothelial dysfunction or insulin resistance. Forty-nine male patients with congenital hypogonadotropic hypogonadism (CHH) (mean age 20.71 ± 1.75 years) and 43 BMI matched healthy male subjects (mean age 21.37 ± 1.04 years) were enrolled. OPG, FGF-23, vitamin D, and asymmetric dimethylarginine (ADMA) levels were measured from the fasting serum samples. The insulin sensitivity was estimated by homeostatic model assessment-insulin resistance (HOMA-IR) formula. Triglycerides, insulin, HOMA-IR, and ADMA levels in the patient group were significantly higher than the values of the control group (p = 0.014, p = 0.002, p = 0.003, p < 0.001, respectively). The OPG, FGF-23, and vitamin D levels of the patients were not significantly different from the healthy controls. In addition, these markers were not correlated to ADMA or HOMA-IR levels. The results show that young and treatment naive subjects with CHH have endothelial dysfunction and insulin resistance when compared to their healthy counterparts. However, the OPG, FGF-23, and vitamin D levels were similar in the 2 groups. In addition, these parameters are not significantly related to the endothelial functions or insulin resistance in these subjects.