Association of Blood Pressure With Cardio-Renal Events and Mortality in Type 2 DM: A National Health Insurance Database.

CONTEXT: The relationship of blood pressure (BP) with cardio-renal events and all-cause mortality in type 2 diabetes mellitus (T2DM) is still controversial. OBJECTIVE: To investigate the optimal BP target in Korean individuals with T2DM. METHODS: Using the Korean National Health Insurance System database, data of individuals with T2DM who underwent regular health checks from January 1, 2007, to December 31, 2007, were extracted (N = 1 800 073). Among them, a total of 326 593 individuals were included in the final study. The study population was divided into 7 groups according to their observed systolic blood pressure (SBP) (<110, 110-119, 120-129, 130-139, 140-149, 150-159, 160-169, and ≥170 mmHg) and diastolic blood pressure (DBP) (<65, 65-69, 70-74, 75-79, 80-84, 85-89, and ≥90 mmHg). Hazard ratios (HRs) of cardio-renal events and all-cause mortality according to BP categories were analyzed. RESULTS: Compared with SBP of 120-129 mmHg and DBP of 75-79 mmHg, SBP of ≥130 mmHg and DBP of ≥ 80 mmHg were associated with an increase in HR of major cardiovascular adverse events (MACEs). SBP of 120-129 mmHg and DBP 75-79 mmHg were associated with the lowest HR of all-cause mortality. Both lower BP (SBP/DBP <120/70 mm) and higher BP (SBP/DBP ≥130/80 mmHg) were associated with an increased HR of all-cause mortality. Contrary to MACE, the lower the SBP, the lower the HR of renal events. CONCLUSION: In patients with T2DM, the optimal cutoff value of BP associated with a lower incidence of MACE and mortality may be 120-129 mmHg for SBP and 75-79 mmHg for DBP. However, lower SBP may be helpful for T2DM patients with a high risk of renal disease.

Clinical features and signaling effects of RET D631Y variant multiple endocrine neoplasia type 2 (MEN2).

BACKGROUND/AIMS: Germline mutations of the rearranged during transfection (RET) gene cause multiple endocrine neoplasia type 2 (MEN2). About 85% of RET mutations in MEN2 occur in codon Cys634. The RET D631Y mutation has recently been discovered, and we have studied its molecular expression and clinical consequences. METHODS: We analyzed the clinical characteristics of a total of 34 D631Y variant MEN2 individuals from seven families. We also constructed wild-type and mutant C630Y, D631Y, and C634R/W expression vectors and investigated their effects on signaling pathways and ability to correct the phenotypes of RET mutant cells. RESULTS: The median ages at diagnosis of pheochromocytoma and medullary thyroid carcinoma (MTC) were higher in patients with RET D631Y variant MEN2 than in those with the C634R/W variant (49:53.5 years vs. 33.5:27 years, respectively), and the penetration of the D631Y mutation with respect to MTC was lower than that of the C634R/W mutation (32.3% vs. 90%). The effects of the mutant vectors on phosphorylation of RET signaling molecules and focus formation were significantly different from those of wild type, but there were no significant differences between the mutants. D631Y scored significantly higher for chemotaxis and wound healing than C630Y, but lower than C634R and C634W. CONCLUSION: We suggest that the tumorigenic potential conferred by the D631Y mutation is lower than that conferred by the C634R/W mutation, but higher than that conferred by C630Y. Thus, the risk level of the RET D631Y variant appears to be higher than that of C630Y and lower than that of C634R/W.

Functional Identification of Compound Heterozygous Mutations in the CYP17A1 Gene Resulting in Combined 17α-Hydroxylase/17,20-Lyase Deficiency.

BACKGROUND: We previously reported a patient with congenital adrenal hyperplasia (CAH) with compound heterozygous mutations in the cytochrome P450 17A1 (CYP17A1) gene. One allele had a p.His373Leu and the other a new p.Glu383fsX36 mutation. The aim of this study was to investigate the functional properties of a new allele present in a compound heterozygote of CYP17A1. METHODS: To understand how p.His373Leu and p.Glu383fsX36 affect P450c17 enzymatic activity, wild type and mutant CYP17A1 cDNAs were cloned into flag-tagged pcDNA3 vector and introduced into human embryonic kidney cells 293T (HEK293T) cells. Protein expression levels of CYP17A1 were then analyzed. And the activities of 17α-hydroxylase and 17,20-lyase of CYP17A1 were evaluated by measuring the conversion of progesterone to 17α-hydroxyprogesterone and of 17α-hydroxypregnenolone to dehydroepiandrosterone, respectively. In addition a computer model was used to create the three-dimensional structure of the mutant CYP17A1 enzymes. RESULTS: Production of the p.His373Leu mutant protein was significantly lower than that of the wild type protein, and the p.Glu383fsX36 protein was hardly produced. Similarly the enzymatic activity derived from the p.His373Leu mutant vector was significantly lower than that obtained from the wild type vector, and little activity was obtained from the p.Glu383fsX36 vector. Three-dimensional modeling of the enzyme showed that p.His373 was located in region important for heme-binding and proper folding. Neither the p.His373Leu nor the p.Glu383fsX36 mutant protein formed a heme-binding structure. CONCLUSION: Enzyme activity measured in both mutants disappeared completely in both 17α-hydroxylase and 17,20-lyase. This result accounts for the clinical manifestations of the patient with the compound heterozygous CYP17A1 mutations.

Mean Platelet Volume Is Closely Associated With Serum Glucose Level but Not With Arterial Stiffness and Carotid Atherosclerosis in Patients With Type 2 Diabetes.

CONTEXT: Mean platelet volume (MPV) has been suggested as a predictive biomarker for cardiovascular disease. OBJECTIVE: This study investigated the association between MPV and subclinical atherosclerosis in Korean patients with type 2 diabetes. METHODS: This cross-sectional study involved 1205 patients with type 2 diabetes mellitus. Both brachial-ankle pulse wave velocity measurements and an ultrasound assessment of carotid atherosclerosis were done. Subclinical atherosclerosis was assessed by the presence of high brachial-ankle pulse wave velocity (>1743 cm/sec), carotid atherosclerosis (intima-media thickness > 0.8 mm or the presence of plaques), and carotid stenosis (≥50% of luminal narrowing). The subjects were stratified into quartiles according to MPV, and the relationship between MPV and subclinical atherosclerosis was analyzed. RESULTS: High MPV quartiles were linearly associated with fasting glucose and glycated hemoglobin but not with diabetic duration or insulin resistance. The prevalence of high pulse wave velocity, carotid atherosclerosis, and carotid stenosis did not differ between the quartiles in men and women. Multivariate logistic regression analyses revealed no association between MPV and high pulse wave velocity, carotid atherosclerosis, and carotid stenosis. CONCLUSIONS: MPV was strongly associated with the severity of glycemic control but not significantly associated with the early and late stages of atherosclerotic vascular changes in type 2 diabetes mellitus patients. Our results suggest that MPV is not a reliable marker for subclinical atherosclerosis in a diabetic population. This is possibly confounded by the close association of MPV with poor glycemic control. Further research is needed to broaden and validate the results.

Upregulation of FGFR1 expression is associated with parathyroid carcinogenesis in HPT-JT syndrome due to an HRPT2 splicing mutation.

Mutations of the HRPT2 gene, which are responsible for hyperparathyroidism-jaw tumor (HPT-JT) syndrome, have been implicated in the development of a high proportion of parathyroid carcinomas. The aim of this study was to investigate differences in expression of the most important genes connected with parathyroid carcinoma between HPT-JT syndrome due to an HRPT2 splicing mutation, normal parathyroid tissue and sporadic parathyroid adenoma. Total RNAs were extracted from parathyroid carcinoma in HPT-JT syndrome harbouring HRPT2 splicing mutation or sporadic parathyroid adenoma and normal parathyroid gland, and subjected to Illumina DASL-based gene expression assay. Unsupervised hierarchical clustering analysis was used to compare gene expression in HPT-JT syndrome, sporadic parathyroid adenoma and normal parathyroid glands. We identified differentially regulated genes in HPT-JT syndrome and sporadic parathyroid adenoma relative to normal parathyroid glands using a combination of Welch's t-test and fold-change analysis. Quantitative PCR, RT-PCR and IHC were used for validation. Sixteen genes differentially regulated in the parathyroid carcinoma were associated with signal pathways, MAPK, regulation of actin cytoskeleton, prostate cancer and apoptosis. FGFR1 expression was confirmed to be significantly upregulated by validation experiments. Our gene expression profiling experiments suggest that upregulated FGFR1 expression appears to be associated with parathyroid carcinoma in HPT-JT syndrome due to an HRPT2 splicing mutation.