Polymorphisms at the ligand binding site of the vitamin D receptor gene and osteomalacia.

Vitamin D receptor (VDR) gene polymorphisms have been suggested as possible determinants of bone mineral density (BMD) and calcium metabolism. In this study, our aim was to determine whether there is an association between VDR gene polymorphism and osteomalacia or not. We determined ApaI and TaqI polymorphisms in the vitamin D receptor gene in 24 patients with osteomalacia and 25 age-matched healthy controls. Serum calcium, phosphorus, ALP, PTH, 25OHD levels were also examined. We used PCR and RFLP methods to test for an association between osteomalacia and polymorphisms within, intron 8 and exon 9 of the VDR gene. When the control and patients were compared for their ApaI and TaqI genotypes there was no relationship between VDR gene allelic polymorphisms and osteomalacia. Whereas a nearly significant difference for A allele was found in the allellic distribution of the patients (p=0.08). Also no association between biochemical data and VDR gene polymorphisms was observed.

[The effects of phase II cardiac rehabilitation programme on patients undergone coronary bypass surgery]. / Koroner baypas geçiren olgularda faz II kardiyak rehabilitasyon programinin etkileri.

OBJECTIVE: To investigate the effects of phase II cardiac rehabilitation in 52 patients undergone coronary artery bypass surgery. METHODS: Gradual walking tests, cardio-pulmonary capacity tests and lipid profile were administered to patients selected for phase II cardiac rehabilitation before and after the programme. Training was started on 12-channel electrocardiogram controlled running bands 3 times a week for 20 min periods for 12 weeks fitting the programme. Low or intermediate level exercise programme was applied to patients. Cleveland Clinic Chronotropic Assessment exercise protocol was used during rehabilitation. RESULTS: As a result of phase II cardiac rehabilitation administered to 52 patients undergone coronary bypass operation, exercise capacity, oxygen consumption, anaerobic threshold, cardiac output mean values (p<0.001) and mean HDL cholesterol level (p<0.05) were found to increase, whereas body mass index, total cholesterol, LDL cholesterol and triglyceride mean levels reduced (p<0.001) significantly. CONCLUSION: In patients who have undergone coronary bypass surgery, phase II cardiac rehabilitation is a very useful programme in improvement of life quality and secondary prevention.

Effect of abdominal obesity on insulin resistance and the components of the metabolic syndrome: evidence supporting obesity as the central feature.

BACKGROUND: Metabolic syndrome includes abdominal obesity, diabetes type 2, hypertension, dyslipidemia, derangements of fibrinolysis, and atherosclerosis. Since abdominal obesity is one of the major components of the insulin resistance syndrome (IRS), an attempt was made to evaluate the interrelationships between the magnitude of obesity and the components of the syndrome. METHODS: A cross-sectional study of 123 subjects with type 2 diabetes, of whom 31 were normal body weight and 92 had varying degrees of obesity was conducted. The participants were investigated in terms of clinical and laboratory findings of IRS. Fasting and 30-min (early) plasma glucose and serum insulin excursions in response to oral glucose challenge (75 g) were determined. The peripheral and hepatic insulin resistance (insensitivity) was calculated by homeostasis model assessment (HOMA). RESULTS: Clinical and biochemical findings were compared with the components of the IRS, and demonstrated that a rise in fasting as well as 30-min insulin secretion increases as abdominal body fat (obesity) increases. There was also a significant and proportional correlation between the magnitude of abdominal obesity and the components of metabolic syndrome. CONCLUSION: Abdominal adiposity appears to have a pivotal role in the development of IRS.

Relationship of transcription factor 7 like 2 gene rs7903146 variation with type 2 diabetes and obesity related parameters.

AIMS: The allele frequencies of transcription factor 7 like 2 (TCF7L2) gene rs7903146 polymorphism in type 2 diabetes mellitus (T2DM) and non-T2DM controls were determined. METHODS: TCF7L2 rs7903146 genotypes were determined with qPCR. RESULTS: The TCF7L2 gene rs7903146 genotype frequencies for homozygous wild type (C/C), heterozygous (C/T) and homozygous polymorphic (T/T) for T2DM patients were determined, respectively, as 71.4%, 14.3%, 14.3% and 72.5%, 11.8%, 15.7% for controls. The weight, length and lean body mass were higher in C/T+T/T compared to C/C carriers. Glucose, insulin, insulin resistance and homeostatic model assessment (HOMA) were nonsignificantly higher in rs7903146C/T+T/T in comparison to C/C. TCF7L2 gene rs7903146 genotypes were not found to interact with drugs. The absence of any difference between genotype frequencies among study groups indicates that no association persists with TCF7L2 gene rs7903146 polymorphism and T2DM. CONCLUSIONS: The effects of rs7903146 variation over some obesity variables suggest that this variation may effect T2DM development via obesity.

Common variants in the ATP-binding cassette transporter 1 gene with decreased HDL-cholesterol levels and coronary artery disease.

BACKGROUND: Our aim was to determine whether the common variants within the coding sequence of ABCA1 gene affects low plasma high-density lipoprotein cholesterol (HDL-C) levels in Turkish patients with coronary artery disease (CAD). The study group was composed of 552 CAD patients, of which 251 had HDL-C levels < or =40 mg/dL, and 301 had HDL-C levels >40 mg/dL. METHODS: PCR-RFLP was used to determine the A2589G and G3456C DNA polymorphisms of the ABCA1 gene. The study group was analyzed for potential clinical predictors of low HDL-C. RESULTS: The GG variant of the ABCA1 gene A2589G polymorphism was found in 3.6% patients within the HDL-C < or =40 mg/dL group and in 4% of HDL-C levels >40 mg/dL group. Frequency distributions of the A2589G genotypes were not found to differ significantly among groups. The CC genotype of the G3456C polymorphism was found in 6.8% of HDL-C < or =40 mg/dL group and in 11.6% individuals of the HDL-C levels >40 mg/dL group. Frequency distributions of the G3456G genotypes were not significantly different among groups. The A2589G genotypes were not found to be effective over the analyzed lipid parameters. Among G3456C genotypes, in CAD patients with HDL-C < or =40 mg/dL the low-density lipoprotein (LDL-C) levels were elevated, whereas HDL-C levels decreased in CC genotype carriers compared to GG and GC. CONCLUSIONS: No significant association was found between cardiovascular endpoints and ABCA1 gene A2589G and G3456C genotypes in this study population.

Association of Resistin Gene 3'-Untranslated Region EX4-44G-->A Polymorphism with Obesity- and Insulin-Related Phenotypes in Turkish Type 2 Diabetes Patients.

Resistin, an adipocyte-secreted hormone, has been associated with obesity, insulin resistance and type 2 diabetes mellitus (T2DM) in some, but not all, rodent models. In humans, the exact function of resistin is unkown. Because 3'-untranslated region (3'-UTR) single nucleotide substitutions (SNPs) have been shown to affect gene expression, we examined the EX4-44G-->A SNP in the 3'-UTR of exon 3 within the resistin gene. The objective of this study was to investigate, for the first time in a Turkish study group, whether the 3'-UTR EX4-44G-->A variation in the resistin gene influences the development of T2DM, obesity and insulin-related phenotypes. We analyzed the genotype frequencies of the EX4-44G-->A polymorphism of the resistin gene in 116 type 2 diabetic and 102 normal subjects. Serum lipids, obesity-related and insulin-related phenotypes were analyzed. No significant difference for genotypic frequencies were observed for the BseRI restriction site in type 2 diabetic patients as compared to controls. Waist-to-hip ratio, BMI, body fat and apoAI levels were found to be affected by resistin genotype. In the control group, BMI (p < 0.01), HIS (p < 0.05) and BF (p < 0.05) levels were found to be elevated, whereas HOMA beta-cell index (p < 0.01) and apo AI (p < 0.05) levels were found to be decreased in GG genotype carriers. In the diabetic group, the GG genotype carriers were found to have higher BMI levels (p < 0.001), waist-to-hip ratio (p < 0.05), body fat (p < 0.01), HOMA (p < 0.001) and fasting insulin (p < 0.05), but lower HbA1c levels in comparison to GC + AA carriers. These data suggest that, in the Turkish study group, the EX4-44G-->A polymorphism of the resistin gene is associated with insulin and obesity-related phenotypes.

Apolipoprotein B gene variants are involved in the determination of blood glucose and lipid levels in patients with non-insulin dependent diabetes mellitus.

We have examined the frequency of the EcoRI, XbaI and MspI RFLPs of the apolipoprotein B (apo B) gene in 110 type 2 diabetic patients and 91 healthy control subjects in order to ascertain whether variation in this gene may influence the development of non-insulin dependent diabetes mellitus (type 2 diabetes). Serum lipids including total-cholesterol (T-Chol), triacylglycerol (TAG), apolipoprotein E (apo E), apolipoprotein AI (apo AI), apolipoprotein B and lipoprotein (a) (Lp(a)) were analysed. Genomic DNA was extracted and the apo B polymorphic regions amplified by the polymerase chain reaction. Regions carrying EcoRI, XbaI, and MspI restriction sites present in the apo B gene were amplified and digested separately by the respective enzymes. No significant difference for genotypic frequencies was observed for the EcoRI, XbaI and MspI restriction sites in type 2 diabetic patients as compared to controls. Type 2 diabetic patients and controls with EcoRI +/+ and XbaI +/+ genotypes had higher apo E levels. The MspI +/+ genotype is more frequent in the patient and control groups with elevated T-Chol. Furthermore, the EcoRI -/-, XbaI -/-, and MspI +/+ genotypes were found to be significantly more frequent in type 2 diabetic patients with higher blood glucose levels. This study identifies the apo B gene polymorphisms in modulating plasma lipid/lipoprotein and glucose levels in patients with type 2 diabetes.

Thiols, malonaldehyde and total antioxidant status in the Turkish patients with type 2 diabetes mellitus.

Non-insulin dependent (Type 2) diabetes mellitus (NIDDM) is a risk factor for cardiovascular diseases (CVD). Oxidative stress mechanisms are often reported to be implied in type 2 diabetes mellitus. In order to determine their clinical relevance, we investigated several plasma indicators in the Turkish patients with NIDDM: (i) homocysteine (Hcy) and cysteine (Cys) which contribute to increase the risk of atherosclerosis during NIDDM, (ii) glutathione (GSH) and cysteinylglycine (CysGly) resulting from GSH degradation catalyzed by gamma-glutamylcysteine transferase (GGT), (iii) malonaldehyde (MDA) as a marker for lipid peroxidation, and (iv) total antioxidant status (TAS). Our main results were evaluated based on sex and diabetic status. In female patients, plasma concentrations of MDA and Hcy were significantly higher than in controls, while GSH levels were significantly lower. In males, a difference between control and diabetic groups was noticed only for Hcy, levels being also higher in patients. In the diabetic group, increase in serum glucose concentration was significantly correlated with increased GGT activity. In both controls and diabetic patients, GGT activity was correlated with a raised Cys concentration and a decreased GSH level. In both controls and diabetic patients, there were significant positive correlations between Cys and Hcy and between GSH and Hcy. We concluded that GSH and MDA levels are clinical indicators for an oxidative process linked to type 2 diabetes mellitus, especially in women.

Lack of association between vitamin D receptor gene polymorphism (BsmI) and osteomalacia.

Vitamin D receptor (VDR) gene polymorphism has been reported to be a determinant of bone formation and intestinal calcium absorption. We carried out this study to assess the role of VDR gene polymorphism in the pathogenesis of osteomalacia. We investigated BsmI polymorphisms in the gene encoding the 1,25 dihydroxyvitamin D receptor in 38 patients with osteomalacia and 31 healthy controls, along with examination of serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and 25 hydroxyvitamin D levels. VDR allelic variants were: BB, 31.6%; Bb, 44.7%; and bb, 23.7% in the osteomalacia patients and BB, 19.4%; Bb, 61.3%; and bb, 19.4% in the controls. Although heterozygotes (Bb) were more frequent than other genotypes in both groups, the BB genotype was found to be more prevalent in osteomalacia than in controls. There was no statistical relationship between VDR genotype and osteomalacia. It is concluded that, in this small group of patients, there was no relationship between VDR allelic polymorphisms and osteomalacia.

Vitamin D receptor alleles, bone mineral density and turnover in postmenopausal osteoporotic and healthy women.

OBJECTIVE: Vitamin D receptor (VDR) gene polymorphisms and bone metabolic markers were investigated as potential genetic markers for osteoporosis in postmenopausal Turkish women. The relationship between their VDR gene polymorphisms and bone states was determined. MATERIALS AND METHODS: Restriction fragment length polymorphisms at the VDR gene locus (i.e., for BsmI, ApaI, and TaqI) was investigated in 75 postmenopausal osteoporotic (53.16 +/- 1.31 years) and 66 healthy (52.62 +/- 1.69 years) Turkish women and the genotypes were related to bone mineral density (BMD) at femoral neck (FN), lumbar spine (L1-4), trochanter, Ward's triangle (Ward's) and metabolic parameters of bone turnover. RESULTS: In osteoporotic women, TaqI genotype-related differences of the VDR gene were found to be significant at all BMD sites; TT genotype had higher L1-4 BMD values than Tt and tt (p < 0.05); tt genotype had significantly lower BMD at FN (p < 0.05), trochanter (p < 0.01), and Ward's (p < 0.05) compared to TT genotype. The tt genotype was found to be associated with higher (p < 0.05) serum osteocalcin levels compared to Tt and TT genotypes in the osteoporotic women, whereas no such association was found for the healthy women. CONCLUSION: Our data showed an association between VDR TaqI genotype and BMD at the FN, L1-4, trochanter and Ward's triangle in nonobese postmenopausal osteoporotic women. Thus the VDR gene Taql polymorphism modulates differences in BMD in the postmenopausal osteoporotic women.

Lipoprotein lipase gene polymorphism and lipid profile in coronary artery disease.

CONTEXT: Lipoprotein lipase (LPL) plays a central role in lipid metabolism, hydrolyzing triglyceride in chylomicrons and very-low-density lipoproteins. The PvuII polymorphic variant of LPL gene is common and might affect risk of coronary artery disease (CAD). OBJECTIVE: Our aim was to determine whether LPL- PvuII polymorphism can be considered to be an independent risk factor or a predictor for CAD in Turkish subjects. DESIGN: We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the previously described C-->T transition that causes a PvuII polymorphism in intron 6 among healthy blood donors of Turkish origin and among angiographically confirmed CAD patients with comparable ethnic backgrounds. RESULTS: For the PvuII genotypes, within the CAD group (n = 80), the +/- genotype was found in 39 individuals (48.8%), whereas 25 (31.3%) carried the +/+ genotype, and 14 (17.5%) carried the -/- genotype. Within the control group (n = 49), the -/- genotype was found in 19 individuals (38.8%), 16 (32.7%) carried the +/- genotype, and 14 (28.6%) carried the +/+ genotype. The genotype frequency distribution was significantly different (P =.049) in the CAD and control study groups. The most frequent genotype among CAD patients was +/-; this genotype was more frequent in patients than in control subjects. However, the -/- genotype was more prevalent in the control group. Lipoprotein lipase-PvuII polymorphism was found to be associated with fasting total cholesterol and low-density lipoprotein cholesterol levels. The +/+ genotype was found to have higher levels of total cholesterol and low-density lipoprotein cholesterol in both the CAD and control groups. CONCLUSION: There was a difference in the distribution of LPL-PvuII genotypes between the healthy subjects and the patients with CAD. Lipoprotein lipase-PvuII polymorphisms were not detected as independent risk factors for CAD in this study group, but had associations with lipid levels.