In Normoglycemic Koreans, Insulin Resistance and Adipocity are Independently Correlated With High Blood Pressure

Low serum uric acid concentration augments insulin effects on the prevalence of metabolic syndrome

AIM

Insulin and uric acid were shown affect the prevalence of Metabolic Syndrome (MetS), but no studies examine their interaction. Therefore, we conducted this study to determine their biological interaction in subjects from central Mexico.

METHODS

433 subjects were enrolled for a cross-sectional study. MetS was defined according to the Harmonizing Definition. Hyperuricemia was defined as ≥7.0 mg/dL in males and ≥5.8 mg/dL in females. Hyperinsulinemia was defined as ≥11.0 μU/mL. Pearson correlation coefficient (r) was calculated to determine the association between uric acid or insulin and MetS. Logistic regression was used to determine the risk (odds ratio) of developing MetS. Biological interactions were determined by the PROCESS Macro and Anderson's method.

RESULTS

Insulin and uric acid levels were elevated in MetS positive group (p < .05) and correlated with the number of MetS components (r = 0.276 and r = 0.166, p < .001, respectively). The interaction between uric acid and insulin was associated with the number of MetS components (PROCESS Model 1, interaction coefficient = -0.009, 95%CI: -0.017 to -0.001, p = .036). Johnson-Neyman analysis suggests the interaction is lost when uric acid concentration increased >7.0 mg/dL. When the cohort was separated by hyperinsulinemia and hyperuricemia, there was a significant risk of developing MetS for subjects with hyperuricemia (odds ratio = 2.3; 95%CI: 1.1-4.8, p < .05), hyperinsulinemia (odds ratio = 3.1; 95%CI: 1.9-4.9, p < .05), or both (odds ratio = 7.4; 95%CI: 3.2-17.2, p < .05); however, there was no multiplicative or additive interaction.

CONCLUSION

Here, we show that uric acid and insulin augments the prevalence of MetS; however, no biological interaction was determined for hyperuricemia and hyperinsulinemia.

Does homeostasis model assessment of insulin resistance have a predictive value for post-coronary artery bypass grafting surgery outcomes?

Objective

This study aims to investigate whether pre-operative Homeostasis Model Assessment Insulin Resistance (HOMA-IR) value is a predictor in non-diabetic coronary artery bypass grafting patients in combination with hemoglobin A1c, fasting blood glucose and insulin levels.

Methods

Eighty one patients who were admitted to Cardiovascular Surgery Clinic at our hospital between August 2012 and January 2013 with a coronary artery bypass grafting indication were included. Patients were non-diabetic with <6.3% hemoglobin A1c and were divided into two groups including treatment and control groups according to normal insulin resistance (HOMA-IR<2.5, Group A; n=41) and high insulin resistance (HOMA-IR>2.5, Group B; n=40), respectively. Pre-operative fasting blood glucose and insulin were measured and serum chemistry tests were performed. The Homeostasis Model Assessment Insulin Resistance values were calculated. Statistical analysis was performed.

Results

There was a statistically significant difference in fasting blood glucose and HOMA-IR values between the groups. Cross-clamping time, and cardiopulmonary bypass time were longer in Group B, compared to Group A (P=0.043 and P=0.031, respectively). Logistic regression analysis revealed that hemoglobin A1c was not a reliable determinant factor alone for pre-operative glucometabolic evaluation of non-diabetic patients. The risk factors of fasting blood glucose and cardiopulmonary bypass time were more associated with high Homeostasis Model Assessment Insulin Resistance levels.

Conclusion

Our study results suggest that preoperative screening of non-diabetic patients with Homeostasis Model Assessment Insulin Resistance may improve both follow-up visit schedule and short-term outcomes, and may be useful in risk stratification of the high-risk population for impending health problems.

Postprandial plasma adiponectin response is reduced in prepubertal premature pubarche girls

The association between premature pubarche (PP) and metabolic syndrome is controversial and not supported by some authors. The aim of this study was to determine insulin resistance syndrome, plasma adiponectin, and fatty acid profile in PP girls to discern potential confounder variables and markers of metabolic disturbances. We studied 22 prepubertal girls with a diagnosis of PP and 20 healthy controls who differed in body mass index (BMI) (19.33 +/- 0.71 vs 17.30 +/- 0.60). We evaluated insulin resistance syndrome components and postprandial response of adiponectin, nonesterified fatty acids, and fatty acid profile after consumption of a standardized breakfast. No lipid disturbances were detected in the PP group. High-density lipoprotein to low-density lipoprotein cholesterol ratio tended to be lower in PP girls (P = .052), but this effect disappeared when data were adjusted for both BMI and age (P = .480). Insulin levels tended to be higher at 2 hours in PP girls, who showed significantly higher C-peptide area under the curve. In contrast, adiponectin at 3 hours after the meal and postprandial adiponectin area under the curve were significantly lower. The PP girls showed significantly higher percentages of eicosapentaenoic acid in total plasma and plasma phospholipids. No differences were found in the postprandial fatty acid clearance rate. In conclusion, PP girls and controls differed in postprandial plasma adiponectin response and in postprandial plasma C-peptide response after both BMI and age adjustment. Cholesterol plasma disturbances were mainly attributable to their higher BMI, although n-3 polyunsaturated fatty acids were higher because of the PP.

Effect of tight control of HbA1c and blood pressure on cardiovascular diseases in type 2 diabetes: an observational study from the Swedish National Diabetes Register (NDR)

AIM

To estimate hazard ratio (HR) of first incident fatal/non-fatal cardiovascular diseases (CVD) in female/male type 2 diabetic patients, with tight versus adverse control of HbA1c and blood pressure (BP) at baseline, age 30-70 years, no baseline CVD, followed for mean 5.7 years.

METHODS

2593 patients with tight control of HbA1c <7.5% and BP < or = 140/90 mmHg (median 6.5%/130/80 mmHg), and 2160 patients with adverse control 7.5-9.0%/141-190/91-110 mmHg (median 8.1%/155/85 mmHg).

RESULTS

The hazard ratio (HR) for CVD with tight/adverse control was 0.67 (0.55-0.80; p<0.001), adjusting for age, sex, duration, hypoglycaemic treatment, smoking, BMI, lipid-lowering drugs, antihypertensive drugs, microalbuminuria. Adjusted HR for myocardial infarction, coronary heart disease, stroke and total mortality were 0.72 (0.56-0.92; p=0.01), 0.69 (0.55-0.86; p<0.001), 0.62 (0.45-0.84; p<0.001), 1.00 (0.72-1.39). The partial population-attributable risk percent for myocardial infarction, stroke and CVD was 23%, 33%, 29% if adverse HbA1c/BP control could be avoided, while 43%, 38%, 39% with overweight and smoking also avoided. Baseline lower BMI and absence of microalbuminuria were associated with tight control.

CONCLUSION

Median difference of HbA1c/BP 1.6%/25/5 mmHg between tight and adverse control considerably reduced the risk of cardiovascular diseases. The findings call for a multi-factorial approach to improve HbA1c, BP, obesity, smoking, and microalbuminuria.

Adiponectin and Insulin Resistance in Obesity-related Diseases

The relationship between insulin resistance and serum adiponectin levels in 400 subjects with different obesity-related diseases was studied. Lean subjects with body mass index (BMI) < 25 kg/m2 were placed in one group and the other five groups of overweight/obese subjects with BMI ≥ 25 kg/m2 were grouped according to disease profile. The homeostasis model assessment insulin resistance (HOMA-IR) index and adiponectin levels were similar in the lean, metabolically normal (MNO) and hypertensive groups, but were different when the dyslipidaemic group was compared with the lean and MNO groups. The type 2 diabetic (DMO) and hypertensive, type 2 diabetic (DMHTO) groups were significantly different from other groups with respect to HOMA-IR index and adiponectin levels. Adiponectin levels were lower in the DMHTO than the DMO group. In multiple regression analysis, adiponectin levels correlated with group categorization independently of age, sex, BMI and HOMA-IR. Hypoadiponectinaemia may play a role in the development of complications of obesity.

The effect of insulin resistance on prognosis of non-diabetic patients who underwent percutaneous coronary intervention

Insulin resistance is an important risk factor for coronary artery disease. However, there has been no data regarding its clinical effect on the outcomes of percutaneous coronary intervention (PCI) in non-diabetic patients. We analyzed 98 non-diabetic consecutive patients (59+/-11.5 yr, male:female=63:35) who underwent elective coronary angiography. The patients were divided into two groups: Group I (n=71; the value of HOMA-IR [homeostasis model assessment of insulin resistance] <2.6) and Group II (n=27; the value of HOMA-IR > or = 2.6). In-hospital and 30-day major adverse cardiac events (MACE) were compared between the two groups. The concentrations of fasting insulin and triglyceride were significantly higher in Group II than in Group I. Significant correlations were observed between the value of HOMA-IR and body mass index (r=0.489, p<0.001), levels of total cholesterol (r=0.204, p=0.045), triglyceride (r=0.334, p=0.001) and apolipoprotein B (r=0.212, p=0.038). PCI was performed in 59 patients (60.2%). In-hospital and 30-day MACE were higher in Group II than Group I (2.4% vs. 27.8%, p=0.008; 2.4% vs. 27.8%, p=0.008). Multivariate analysis revealed that the value of HOMA-IR > or = 2.6 was an independent predictor of MACE. Increased HOMA-IR level is an important prognostic indicator in non-diabetic patients underwent PCI.

Vanadyl sulfate administration protects the streptozotocin-induced oxidative damage to brain tissue in rats

Diabetes mellitus manifests itself in a wide variety of complications and the symptoms of the disease are multifactorial. The present study was carried out to investigate the effects of vanadyl sulfate on biochemical parameters, enzyme activities and brain lipid peroxidation, glutathione and nonenzymatic glycosylation of normal- and streptozotocin-diabetic rats. Streptozotocin (STZ) was administered as a single dose (65 mg/kg) to induce diabetes. A dose of 100 mg/kg vanadyl sulfate was orally administered daily to STZ-diabetic and normal rats, separately until the end of the experiment, at day 60. In STZ-diabetic group, blood glucose, serum sialic and uric acid levels, serum catalase (CAT) and lactate dehydrogenase (LDH) activities, brain lipid peroxidation (LPO) and nonenzymatic glycosylation (NEG) increased, while brain glutathione (GSH) level and body weight decreased. In the diabetic group given vanadyl sulfate, blood glucose, serum sialic and uric acid levels, serum CAT and LDH activities and brain LPO and NEG levels decreased, but brain GSH and body weight increased. The present study showed that vanadyl sulfate exerted antioxidant effects and consequently may prevent brain damage caused by streptozotocin-induced diabetes.

A Positive Association between Leptin and Blood Pressure of Normal Range in Japanese Men

The results of previous studies on the relationship between leptin and blood pressure are discordant. We investigated to what extent the serum leptin level was related to blood pressure independent of the degree of insulin resistance. The subjects were 1916 men aged 34-69 years whose mean body mass index (BMI) was 23.0 kg/m2. Blood pressure was regressed by leptin concentrations with adjustments for age, BMI, insulin resistance, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, physical activity, drinking habits and smoking status. Leptin was associated with diastolic blood pressure (DBP) (standardized beta: 0.092, p = 0.003), but not with systolic blood pressure (SBP) (standardized beta: 0.035, p = 0.25), although insulin resistance was positively associated with both SBP and DBP (standardized beta: 0.175 for SBP, p < 0.001 and 0.114 for DBP, p < 0.001) among all subjects. After subjects were divided into those with normal blood pressure (SBP <130 mmHg and DBP <85 mmHg) and those with higher blood pressure, leptin was positively and significantly associated with DBP (standardized beta: 0.106, p = 0.012) independent of the degree of insulin resistance, but not with SBP (standardized beta: 0.064, p = 0.13) among subjects in the normal blood pressure range. Among the subjects with higher blood pressure, however, neither the association of leptin with SBP nor that of leptin with DBP was statistically significant. These findings suggest that leptin may maintain and increase arterial tone, resulting in the elevation of DBP only within normal blood pressure range. It is also likely that leptin is a physiological mediator--or at least a marker--of some degree of DBP elevation in obesity.

Predictors of successful long-term blood pressure control in type 2 diabetic patients: data from the Swedish National Diabetes Register (NDR)

BACKGROUND

Hypertension in patients with diabetes is a well recognized cardiovascular risk factor for which the benefits of treatment are strongly evidence based. Less is known about predictors for successful long-term blood pressure control in these patients, including the potential role of body mass index (BMI), glycaemic control, microalbuminuria and smoking.

MATERIAL AND METHODS

We used longitudinal data on risk factor levels from repeated clinical surveys of 1759 type 2 diabetic patients in the Swedish National Diabetes Register (NDR), a nationwide annual registration of quality indicators in diabetes care. Subjects with successful blood pressure (BP) control (systolic BP < 135 mmHg and diastolic BP < 85 mmHg) at baseline in 1997, in 2001, and at follow-up in 2003, were compared to subjects with BP control >or= 135/85 mmHg.

RESULTS

Logistic regression analysis disclosed that successful BP control during the study period was predicted by lower BMI (P < 0.001), a lower frequency of microalbuminuria (P = 0.002), and lower age (P < 0.001) at baseline in 1997, and was still associated with lower BMI (P < 0.001), a lower frequency of microalbuminuria (P = 0.01) and lower age (P < 0.001) at follow-up. Successful BP control was also associated at follow-up with a lower frequency of the metabolic syndrome (30 versus 75%) and lower predicted 10-year risks [United Kingdom Prospective Diabetes Study (UKPDS) Risk Engine] of coronary heart disease (14 versus 29%) and stroke (10 versus 22%) (all P < 0.001).

CONCLUSION

A lower BMI and absence of microalbuminuria were strong independent predictors of long-term successful BP control in type 2 diabetic patients, also characterized by a lower frequency of the metabolic syndrome and lower 10-year risk of cardiovascular disease. This implies the long-term benefits on BP control of lifestyle measures as well as control of microalbuminuria.

Relationship between serum uric acid concentration and insulin resistance and metabolic syndrome

BACKGROUND

Associations between hyperuricemia, cardiovascular diseases and diabetes have been reported, but few of the studies have been conducted in the Korean population. The present study examined a Korean adult population with respect to the relationships between serum uric acid concentrations and hypertension, insulin resistance, and the risk factors of metabolic syndrome.

METHODS AND RESULTS

A total of 53,477 subjects were divided into 4 groups according to serum uric acid quartiles. The incidence of hypertension in all subjects was higher in the first quartile than in the third plus fourth quartile (odds ratio (OR) 1.192, p < 0.001). Homeostasis model assessment index was found to be associated with serum uric acid concentration in all subjects (OR 1.193, p < 0.001), and the serum uric acid concentration was positively correlated with the risk factors of metabolic syndrome. In addition, the number of metabolic syndrome variables increased as serum uric acid concentration increased.

CONCLUSIONS

Serum uric acid concentration was found to be independently correlated with hypertension, insulin resistance and the risk factors of metabolic syndrome. In addition, even those with a serum uric acid concentration in the normal range showed an increased risk of metabolic syndrome as serum uric acid concentration increased.