Gestational diabetes mellitus (GDM) is a glucose intolerant condition that affects 14% of all pregnancies. Diabetes mellitus (DM) occurs in 30 - 70% of patients with GDM after delivery. DM and GDM are associated with structural and functional deterioration of the renovascular system. Our aim is to investigate the association Glu- 298Asp polymorphism of the endothelial nitric oxide synthase (eNOS) gene with serum nitric oxide levels and microalbuminuria in patients with GDM and healthy pregnancies. Serum nitric oxide (NO) levels, urinary excretion of albumin and Glu298Asp polymorphism of the eNOS gene were analyzed in 68 patients with GDM and 73 healthy controls. High performance liquid chromatography (HPLC-Griess) method was used to analyze serum NO levels. Microalbuminuria was evaluated by rate nephelometry method. The Glu298Asp polymorphism of the eNOS gene was determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Nitric oxide, glucose, creatinine, and microalbuminuria were significantly different between the patients and the control subjects (p = 0.001, p = 0.001, p = 0.002, and p = 0.005, respectively). There was a significant difference between groups in terms of the ratio of GG/GT+TT of eNOS gene Glu- 298Asp (p = 0.02). The patients with GT+TT genotype had significantly higher microalbuminuria levels and lower NO concentrations (22.16 vs. 9.51, p = 0.005, and 10.56 vs. 12.73, p = 0.021, respectively). The presence of T allele of eNOS gene is an independent predictor of microalbuminuria (OR: 2.346, 95% confidence interval: 1.247 - 5.238, p = 0.02) as well as serum glucose and NO concentration. The G894T polymorphism of eNOS gene and decreased NO concentration seem to be independent predictors of increased urinary excretion of albumin in patients with GDM. Determining the frequency of eNOS gene G894T polymorphism may help to identify pregnancies at increased risk of microalbuminuria.

Bone mineral disorders are being increasingly seen among diabetic populations as the frequency of diabetes mellitus (DM) is rising at an alarming rate. Our aim is to examine the relationship between glycemic control and bone turnover markers like osteocalcin (OC), C-terminal carboxy telopeptide (CTX), and bone-specific alkaline phosphatase (ALP) in patients with type 2 diabetes, and the effects of anti-diabetic regimens on these markers. A total of 80 newly diagnosed type 2 DM patients were enrolled into the study and divided into two groups according to glucose regulation (group 1 HbA1c < 7 and group 2 HbA1c ≥ 7). They were also classified into three groups according to antidiabetic regimen. Physical examination findings, demographic characteristics, and anti-diabetic regimens of the patients were recorded. Hemogram and biochemical parameters were studied after 12 hours of fasting. Serum levels OC and CTX were examined by ELISA method. Bone-specific ALP was examined by Chemiluminesence immuneassay (CLIA) method. Bone densitometry was performed on the 2016 model Stratos DR device of DMS brand, and T scores of the patients were recorded. All parameters were repeated at the 6th month of the study. Serum vitamin D and OC levels of group 1 were higher, while ALP was higher in group 2. However, we failed to determine a significant difference in CTX levels between the groups. OC levels were enhanced only in patients receiving metformin plus vildagliptin therapy. The CTX levels increased in all groups, whereas they decreased in the metformin plus DPP-4 group. Better glucose regulation is associated with better bone formation, and among three groups metformin plus vildagliptin therapy has a favorable effect on both bone formation and resorption.