Prehypertension is associated with insulin resistance

Low-Density Lipoprotein Cholesterol Is Not a Major Determinant of High-Sensitivity C-Reactive Protein Levels in People Without Known Diabetes Mellitus

Background: It has been well established that high-sensitivity C-reactive protein (hs-CRP) is strongly associated with obesity, insulin resistance, high blood pressure, and dyslipidemia. However, the effects of different lipid parameters on hs-CRP levels are less deliberated. The purpose of the study was to compare the relative contribution of triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) to the levels of hs-CRP. Methods: Three hundred seventy-eight subjects without known history of diabetes were recruited for the study. No concomitant antilipid or antidiabetes agents were allowed. Each subject received anthropometric measurements, fasting sampling for lipid profile and hs-CRP, and a 75-gram oral glucose tolerance test for the measurements of insulin resistance (surrogated by insulin sensitivity index ISI0,120). Results: Levels of hs-CRP levels were positively correlated with Log (TG) and negatively correlated with HDL-C in partial correlation after adjustments for confounding variables, but not with LDL-C. The hs-CRP levels in the three groups by tertiles of LDL-C were similar. Subsequently, we found that body mass index (first step), Log (ISI0,120) (second step), and Log (TG) (third step) independently predicted the variance of Log (hs-CRP) in stepwise multiple regression. However, both HDL-C and LDL-C failed to be entered into the models to explain Log (hs-CRP). Conclusions: Our data demonstrated that Log (TG) was a major lipid determinant of hs-CRP levels. The contribution of LDL-C to the levels of hs-CRP might be insignificant.

Ten-year atherosclerotic cardiovascular disease risk prediction for postmenopausal women: Impacts of isolated postchallenge hyperglycemia

Isolated postchallenge hyperglycemia (IPH) is a type of diabetes mellitus defined as 2-h glucose ≥200 mg/dL but fasting glucose <126 mg/dL. The purpose of the study was to assess impacts of IPH on 10-year atherosclerotic cardiovascular disease (ASCVD) risk scores in postmenopausal women. This study analyzed data from 428 postmenopausal women who underwent oral glucose tolerance test at a medical center. Ten-year ASCVD risk was evaluated by using Pooled Cohort Equations. Logistic regression analysis was performed to estimate odds ratios for having high 10-year ASCVD risk scores (≥5%) among these women. The subjects with IPH had higher systolic blood pressure and worse lipid profile than those without IPH. Ten-year ASCVD risk scores for postmenopausal women with IPH were calculated under 2 scenarios: the IPH women were considered non-diabetic, they were designated as patients with DM. The median ASCVD risk score of the participants with IPH increased significantly from 3.7% under scenario 1 to 7.1% under scenario 2. Approximately 20% women with IPH were re-categorized from risk category of <5% to ≥7.5% once they were identified as patients with DM (scenario 2). The results of logistic regression analyses showed that IPH was independently positively associated with 10-year ASCVD risk scores ≥5% under both scenarios. Postmenopausal women with IPH were characterized by unfavorable cardiovascular risk profile and high predicted 10-year ASCVD risk. Knowing the women's hidden DM status would significantly alter their risk categorization.

A positive association between interleukin-1 receptor antagonist and insulin resistance in postmenopausal women

OBJECTIVE

The purpose of this study was to determine whether higher circulating interleukin-1 receptor antagonist (IL-1Ra), an anti-inflammatory cytokine, was associated with insulin resistance in postmenopausal women.

METHODS

We measured IL-1Ra concentrations in 160 naturally postmenopausal women without a history of diabetes mellitus. A Pearson coefficient was computed to assess the relationship between plasma IL-1Ra and homeostasis model assessment of insulin resistance (HOMA-IR). The association between HOMA-IR and IL-1Ra plasma level above the median was assessed by logistic regression. Linear regression was used to explore the determinants of IL-1Ra plasma levels.

RESULTS

A significant positive correlation existed between IL-1Ra and HOMA-IR (r = 0.42, p < .0001). The upper-tertile group of HOMA-IR was associated with approximately 4.5-fold increased risk of plasma IL-1Ra level above the median compared with the low-tertile group after adjustments. When multiple correlates were entered into the regression model simultaneously, only Log HOMA-IR remained significantly related to Log IL-1Ra (p = .007).

CONCLUSIONS

Our results demonstrated a positive association between plasma IL-1Ra and insulin resistance in postmenopausal women. This analysis suggested that insulin resistance was an important determinant of circulating IL-1Ra for these women.

Circulating bone morphogenetic protein-9 levels are associated with hypertension and insulin resistance in humans

It has been demonstrated that bone morphogenetic protein-9 (BMP-9) may have an important role in vascular development and stability. However, the association of circulating BMP-9 with essential hypertension (HTN) has not been established in humans. The objective of this study is to observe the changes of circulating BMP-9 levels in patients with HTN and to investigate the association of circulation BMP-9 and insulin resistance (IR) in a cross-sectional study. Two hundred twenty-five individuals, including 132 patients with hypertension, and 93 healthy controls, were included in the present study. Circulating BMP-9 concentrations were measured with an ELISA kit. The association of circulating BMP-9 with other parameters was analyzed. When compared with healthy subjects, circulating BMP-9 concentrations were markedly lower in HTN patients (46.20 [31.85-62.80] vs. 77.21 [39.33-189.15], P < .01) and correlated negatively with blood pressure and the homeostasis model assessment of insulin resistance (P < .05 or P < .01). Decreasing levels of BMP-9 were independently and markedly related to HTN. In a multiple linear regression analysis, only systolic blood pressure and free fatty acid concentrations were independently associated with circulating BMP-9. Our findings suggest that BMP-9 may be a serum biomarker for HTN and IR.

β-Cell function in postmenopausal women with isolated post-challenge hyperglycemia

BACKGROUND

Isolated post-challenge hyperglycemia (IPH) is an early stage of type 2 diabetes mellitus (T2DM), with fasting glucose <126 mg/dL and 2-h glucose ≥200 mg/dL. Observations of insulin secretion profile in subjects with IPH may provide an insight into the pathogenesis of T2DM in older women.

METHODS

We recruited 555 naturally postmenopausal women without a history of T2DM to the present study. All participants received a 75-g oral glucose tolerance test to determine whether they had IPH. General linear models were used to compare differences in glucose metabolism among subjects.

RESULTS

Early phase insulin responses to oral glucose were significantly decreased in women with IPH versus those with impaired glucose tolerance (IGT) and normal glucose tolerance (geometric mean [95% confidence interval] insulinogenic index 61 [54-79] vs 90 [83-97] and 105 [96-116], respectively; P  < 0.0001). In addition, there were significant decreases in late-phase insulin release as metabolic status shifted from normal glucose tolerance to IGT to IPH. In the present cohort, the relative contribution of early insulin secretion to 2-h glucose was no longer significant ( P  = 0.15) after multiple factors, including indicators of insulin resistance and late-phase insulin release, were entered into the regression model simultaneously.

CONCLUSIONS

The results demonstrate that postmenopausal women with IPH are characterized by impaired β-cell function. There were significant decreases in early and late-phase insulin release as glucose intolerance escalated. Disturbance in β-cell function seems to be an important factor associated with early T2DM in postmenopausal women.

Association between changes in systolic blood pressure and incident diabetes in a community-based cohort study in Korea

An association between hypertension and diabetes has been reported; however, the temporal relationship of blood pressure changes and incident diabetes has not been fully investigated in the general population. We examined whether increasing blood pressure is associated with the risk of developing diabetes among community-dwelling Korean adults. This study included 2225 participants (859 men and 1366 women) aged 27-87 years from the Korean Genome Epidemiology Study. The participants were free of diabetes and cardiovascular disease at baseline. Incident diabetes was defined as fasting blood glucose⩾126 mg dl^-1 or hemoglobin a1c ⩾6.5% (48 mmol mol^-1) at follow-up examination and/or a physician's diagnosis of diabetes during the follow-up period. The effects of the baseline level and change in blood pressure on the risk of incident diabetes were assessed by multivariate logistic regression analysis. During the mean follow-up of 2.6 years, new-onset diabetes was observed in 5.0% (43/859) of the men and 3.4% (47/1366) of the women. In the multivariate model, the baseline systolic blood pressure was not significantly associated with incident diabetes (adjusted odds ratio 0.93 per 10 mmHg, P=0.747). However, an increase in systolic blood pressure during the follow-up period was independently associated with incident diabetes (adjusted odds ratio 5.53 per 5 mmHg per year, P=0.002) after adjusting for the baseline blood pressure and other potential confounders. Increasing blood pressure, but not a high baseline blood pressure, was independently associated with the risk of diabetes in Korean adults.

Higher normal range of fasting plasma glucose still has a higher risk for metabolic syndrome: a combined cross-sectional and longitudinal study in elderly

INTRODUCTION

It is well known that higher fasting plasma glucose (FPG) is associated with metabolic syndrome (MetS). This relationship still exists even the FPG is within the normal range. However, most of these studies did not exclude subjects who were on medications which would affect the results of the studies. At the same time, there is no longitudinal study done to validate this correlation, especially in elderly. In this study, the relationships between normal FPG and MetS were evaluated.

METHOD

We randomly selected 57,517 subjects who were ≥ 60-years old from health screening centre. In the first part of study, subjects were enrolled in the cross-sectional study to find out the optimal cut-off value of FPG with higher chances to have MetS. In the second part of current study, subjects with MetS at baseline were excluded from the same study group, and performed a median 5.3-year longitudinal study.

RESULTS

There were 18,287 subjects enrolled in this study. In the first part of study, the cross-sectional study, optimal cut-off values of FPG were determined by the ROC curve and the sensitivity for these cut-off values were 56.6% in men and 60.9% in women, respectively. The result showed that lower FPG is healthier than the higher (log-rank test, p < 0.001). During the follow-up period, 5039 subjects showed hazard ratios of 2.09 for men and 1.884 for women developing future MetS.

CONCLUSION

Our study is the first longitudinal design in elderly and showed that older subjects with higher FPG proved to have higher risk of Mets even the FPG is still within its normal range.

High prevalence of metabolic syndrome in a middle-aged and elderly population with prehypertension in Tianjin

BACKGROUND

Prehypertension has been reported as being correlated with future cardiovascular risk and end-organ damage in middle-aged and elderly persons, and also playing an important role in metabolic syndrome (MetS). The association between prehypertension and MetS has rarely been reported among urban adults in Tianjin, China.

METHODS

In this cross-sectional study, a total of 1176 participants aged 40-70 years (524 males and 652 females) were enrolled after excluding participants with hypertension or treated hypertension. Participants were divided into two groups [optimal blood pressure (BP) and prehypertension] based on the classification of BP from the JNC-7. The definition of MetS was as per the International Diabetes Federation standard. An adjusted logistic regression model was used to assess relationships between prehypertension and MetS.

RESULTS

The prehypertension group had a significantly higher odds ratio (OR) than the optimal BP group for abnormal waist circumference (WC), fasting plasma glucose (FPG) and triglycerides (TG). In addition, the prehypertension group had a higher OR (3.12; 95% confidence interval 2.34-4.18) for having MetS after adjusting for potential confounders.

CONCLUSIONS

The risk of having MetS was significantly associated with prehypertension in middle-aged and elderly persons in Tianjin. Stricter control of BP in this age group is warranted.

Prevention of metabolic disorders with telmisartan and indapamide in a Chinese population with high-normal blood pressure

High-normal blood pressure is considered a precursor of stage 1 hypertension that is associated with metabolic disorders. This study aims to investigate whether the pharmacologic treatment of high-normal blood pressure affects metabolism, especially in abdominally obese individuals, and the pharmacoeconomics of two antihypertensive agents, telmisartan and indapamide. Subjects with high-normal blood pressure were randomly assigned to receive telmisartan, indapamide or placebo for 3 years. All the subjects were instructed to modify their lifestyle to reduce blood pressure throughout the study. A total of 221 subjects were randomly assigned to telmisartan, 213 to indapamide and 230 to placebo. After the 3-year intervention, blood pressure was lower in the telmisartan and indapamide groups (P<0.05), FPG in the telmisartan group was lower during the first 2 years (P<0.05) and no characteristic differences were found in those with abdominal obesity among the three groups (P>0.05). The percentage of subjects with metabolic syndrome was significantly decreased in the telmisartan and indapamide groups (P<0.05), but was only significantly decreased in the telmisartan group for subjects with abdominal obesity (P<0.05). The acquisition cost for telmisartan was ~1.86 times higher than for indapamide for a similar antihypertensive effect. The intervention for high-normal blood pressure with telmisartan and indapamide appeared to be feasible and reduced the risk of metabolic syndrome. Telmisartan was more effective, whereas indapamide had better pharmacoeconomic benefits.

Hyperhomocysteinemia, Insulin Resistance and High HS- CRP Levels in Prehypertension

BACKGROUND

Pre-hypertension refers to blood pressure in the range of 120 to 139 mm of Hg / 80 to 89 mm of Hg and its prevalence is increasing in India. Previous studies have documented the increase in homocysteine, C-reactive protein and insulin resistance and their role in the development of hypertension. In recent years much attention has been focused on subjects with prehypertension, as the risk for development of cardiovascular disease is higher in these subjects compared to those with normal blood pressure.

OBJECTIVES

To evaluate the serum homocysteine, hs-CRP level and insulin resistance in subjects with prehypertension.

MATERIALS AND METHODS

Sixty prehypertensives and 32 normotensives were recruited according to Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of blood pressure (JNC 7) guidelines. Serum homocysteine, vitamin B12, folate, insulin, hs-CRP and lipid profile were analysed. Independent t-test was carried out to compare two groups and pearson correlation analyses were carried out between various parameters with systolic blood pressure (SBP) and diastolic blood pressure (DBP).

RESULTS

Cardiovascular risk factors like serum homocysteine, insulin resistance and inflammatory marker hs-CRP were significantly increased in prehypertensives. Total cholesterol, TG, LDL-C and VLDL-C were significantly increased when compared to normotensives. Serum homocysteine correlated positively and vitamin B12 and folate negatively with Systolic Blood Pressure.

CONCLUSION

The present study concludes that the established cardiovascular risk factors, homocysteine, insulin resistance, and hs-CRP which have roles in the etiopathogenesis of hypertension, were elevated in subjects with prehypertension. Thus, early detection and life style modification may reduce the risk or delay the onset of hypertension and other cardiovascular complications.

Metabolic syndrome in normoglycaemic elderly men

OBJECTIVE

Type-2 diabetes is mainly the metabolic defect involving multiple organs. To conclude their intricate relationships, the term 'ominous octet' had been proposed to denote this phenomenon. In this study, we enrolled older men without any medications for MetS components to further elucidate the relationships between normoglycaemic state and MetS.

METHODS

We enrolled male subjects with FPG less than 100 mg/dl and aged 65 and older undergoing routine health check-ups in Taiwan. After excluding subjects taking medications that might affect the components of MetS, a total of 6679 men were eligible for the analysis. Study subjects were further grouped into FPG tertiles (< 91 mg/dl, 92-95 mg/dl and > 95 mg/dl for tertil 1, tertil 2 and tertil 3, respectively).

RESULTS

There was a significant trend between the FPG and percentages of subjects having MetS (p = 0.009). The relationships between the MetS components were higher in FPG 2 and FPG 3 than FPG 1. In simple correlation, all of the MetS and LDL-C were positively correlated with FPG level and multiple regression further confirmed the same result except for HDL-C that became non-significant. Subjects in FPG3 had significantly higher ORs (ORs = 1.19) for having MetS than those in FPG1.

CONCLUSIONS

In conclusion, higher FPG still had higher risk of having MetS in normoglycaemic range in elderly male. More strict FPG level control may be valuable in CVD prevention and warrants further investigations.

High normotension is associated with higher metabolic syndrome risk in postmenopausal women

AIM

Cardiovascular disease and diabetes are important causes for mortality in older people. Both hypertension and prehypertension are correlated with them. Recently, health promotion and disease prevention in postmenopausal women have become an essential issue of public health policy. The present study aimed to evaluate whether the harmful effects of blood pressure (BP) could still be found in normotensive postmenopausal women (below 120/80 mmHg).

METHODS

A total of 4539 normotensive postmenopausal women aged 51 years or older, undergoing routine health examinations, were enrolled in the cross-sectional analyses. To mitigate the effect of age on BP, participants within the same age were divided into tertiles according to their systolic BP (SBP). Then, participants in the low-SBP tertile of each age stratum were pooled together to form a larger group (low-normal SBP group [LNSBP]). Similarly, the middle- and high-normal SBP were grouped accordingly (MNSBP and HNSBP). Metabolic syndrome (MetS) was considered to be a surrogate for future cardiovascular disease and diabetes.

RESULTS

The study showed that HNSBP bore a higher likelihood of having abnormal MetS components, elevated low-density lipoprotein cholesterol levels and a higher odds ratio (1.46; 95% confidence interval 1.17-1.81) for having MetS than LNSBP. In contrast, age, body mass index, fasting plasma glucose and low-density lipoprotein cholesterol were significantly related to SBP in multiple regression analysis.

CONCLUSIONS

The risk of having MetS was significantly associated with higher SBP even within normotension. Primary prevention, such as lifestyle modification, and more strict control of BP should be stressed in postmenopausal women.

Increased incidence of metabolic syndrome in older men with high normotension

INTRODUCTION

Hypertension and prehypertension are correlated with future cardiovascular disease (CVD) and diabetes. Whether these harmful effects of the blood pressure (BP) could be found in normotensive is of interest.

METHODS

In this cross-sectional study, totally 2388 normotensive older men aged 65-80 years undergoing routine health examinations were enrolled. To eliminate the influence of age on BP, subjects were initially grouped in each age stratum. Then in each age-stratum, subjects were further grouped into low, middle and high-tertile systolic BP (SBP) subgroups. Finally, all the low-tertile subgroups in each age stratum were gathered to form Group-1. Similarly, Group-2 (middle-tertile) and Group-3 (high-tertile) were also created. Metabolic syndrome (MetS) was regarded as having risks for future CVD and diabetes.

RESULTS

Age, waist circumstance (WC), fasting plasma glucose (FPG) and log triglyceride (TG) were independently and significantly correlated with SBP by multiple linear regression analysis. On the other hand, logistic regression showed that Group-3 had significant higher odds ratios (ORs) for having abnormal WC, FPG and TG. In addition, Group-3 presented a 1.55-fold OR (p < 0.001) for having MetS than Group-1.

CONCLUSIONS

In normotensive older men, the risk for having MetS was significantly associated with higher SBP. Primary prevention of hypertension should be stressed.

Prehypertension in dyslipidemic individuals; relationship to metabolic parameters and intima-media thickness

INTRODUCTION

Like hypertension, prehypertension is associated with cardiovascular disease.

AIMS

The aim of this study was to evaluate: a) the prevalence of prehypertension/hypertension in individuals with various dyslipidemic phenotypes; b) the relation between blood pressure (BP) and other risk factors for atherosclerosis; c) atherogenic potential of prehypertension by the assessment of intima-media thickness of the arteria carotis communis (IMT).

METHODS

667 clinically asymptomatic subjects were divided into four dyslipidemic phenotypes (DLP) according to apolipoprotein B (apoB) and triglycerides (TG): DLP1 (n=198, normo-apoB/normo-TG), DLP2 (n=179, normo-apoB/hyper-TG), DLP3 (n=87, hyper-apoB/normo-TG), DLP4 (n=203, hyper-apoB/hyper-TG). DLP1 served as a control group.

RESULTS

There was significantly higher prevalence of prehypertension and hypertension in subjects with dyslipidemia (DLP2 43.0%, 41.3%; DLP3 42.5%, 29.9%; DLP4 42.4%, 47.8%) than in normolipidemic individuals (DLP1 32.8%, 20.2%). Systolic and diastolic blood pressure (SBP + DBP) correlated with age, total cholesterol, TG, non-HDL-cholesterol, body mass index and waist circumference; SBP additionally with C-peptide, fasting glycemia; DBP additionally with apoB, homeostasis model assessment (HOMA) and plasminogen activator inhibitor-1. The IMT of hypertensive and of prehypertensive subjects was higher than that of subjects with normal BP in all DLPs.

CONCLUSIONS

The prevalence of prehypertension was higher in all dyslipidemic patients. The common prevalence of prehypertension/hypertension was highest in the hypertriglyceridemic subjects. Prehypertensive and hypertensive patients had higher IMT than normotensive individuals in all DLPs.

Utilization of dietary glucose in the metabolic syndrome

This review is focused on the fate of dietary glucose under conditions of chronically high energy (largely fat) intake, evolving into the metabolic syndrome. We are adapted to carbohydrate-rich diets similar to those of our ancestors. Glucose is the main energy staple, but fats are our main energy reserves. Starvation drastically reduces glucose availability, forcing the body to shift to fatty acids as main energy substrate, sparing glucose and amino acids. We are not prepared for excess dietary energy, our main defenses being decreased food intake and increased energy expenditure, largely enhanced metabolic activity and thermogenesis. High lipid availability is a powerful factor decreasing glucose and amino acid oxidation. Present-day diets are often hyperenergetic, high on lipids, with abundant protein and limited amounts of starchy carbohydrates. Dietary lipids favor their metabolic processing, saving glucose, which additionally spares amino acids. The glucose excess elicits hyperinsulinemia, which may derive, in the end, into insulin resistance. The available systems of energy disposal could not cope with the excess of substrates, since they are geared for saving not for spendthrift, which results in an unbearable overload of the storage mechanisms. Adipose tissue is the last energy sink, it has to store the energy that cannot be used otherwise. However, adipose tissue growth also has limits, and the excess of energy induces inflammation, helped by the ineffective intervention of the immune system. However, even under this acute situation, the excess of glucose remains, favoring its final conversion to fat. The sum of inflammatory signals and deranged substrate handling induce most of the metabolic syndrome traits: insulin resistance, obesity, diabetes, liver steatosis, hyperlipidemia and their compounded combined effects. Thus, a maintained excess of energy in the diet may result in difficulties in the disposal of glucose, eliciting inflammation and the development of the metabolic syndrome.

Relationship of blood pressure and cardiovascular disease risk factors in normotensive middle-aged men

We conducted this study to investigate whether subjects with high-normal systolic blood pressure (SBP) have an increased risk of cardiovascular disease (CVD) and/or diabetes compared to subjects with low-normal SBP, using metabolic syndrome (MetS) as a risk factor for future CVD/diabetes.The study included 6133 apparently healthy Taiwanese men aged 40-65 years. All subjects were normotensive, and none took medication for any abnormal MetS component. To avoid the effect of age on blood pressure, we stratified patients first by age then by SBP (that is, low, middle, and high SBP). We pooled all the low, middle, and high SBP groups from the different age strata to create 3 larger groups (Group 1, Group 2, and Group 3, respectively). The MetS components in subjects with the lowest SBP (Group 1) were compared with those in the other 2 groups. All of the MetS components, except for high-density lipoprotein cholesterol (HDL-C), were significantly lower in Group 1. Thus, it was not surprising that Group 2 and Group 3 had significantly higher odds ratios for abnormal body mass index, fasting plasma glucose, low-density lipoprotein-cholesterol (LDL-C), and triglycerides than Group 1 (but not for HDL-C). Specifically, Group 3 had a 1.7-fold higher odds ratio (p < 0.001) for having MetS than Group 1. Age, body mass index, fasting plasma glucose, LDL-C, and log triglycerides correlated significantly with SBP. In multivariate linear regression analysis, we found that only body mass index, fasting plasma glucose, and log triglycerides remained significantly related to SBP. Among them, body mass index had the highest β value.In conclusion, the level of SBP was highly correlated with body mass index, fasting plasma glucose, and triglycerides in subjects with normotension. Although there is not a cause-and-effect relationship, the risk of CVD and diabetes was significantly associated with an elevation of SBP, even when the SBP remained within the normal range. Further studies are needed to determine whether normotensive subjects would benefit from medical management.

The effect of body mass index and fasting glucose on the relationship between blood pressure and incident diabetes mellitus: a 5-year follow-up study

There is no consensus on the relationship between high blood pressure (BP) and incident diabetes mellitus (DM). Therefore, the aim of the current study was to investigate the independent association between BP and incident DM and identify the metabolic components that influence incident DM in Korean subjects. The current study included 14 054 non-diabetic subjects (mean age of 41 years) at the start of the study who were followed for an average of 5 years. We measured the risk for incident DM according to the subjects' baseline BP. Subjects were separated into three groups as follows: normotensive (<120/80 mm Hg), pre-hypertensive (120/80 mm Hg ⩽BP <140/90 mm Hg) and hypertensive (⩾140/90 mm Hg). The overall incidence of DM was 1.8% (246 subjects), comprising 0.9% of the normotensive group, 1.9% of the pre-hypertensive group and 4.0% of the hypertensive group (P<0.01). Within the hypertensive group, subjects with high body mass index (BMI) and high fasting-glucose levels were 40 times more likely to develop DM compared with those with low BMI and low glucose levels (0.3 vs. 13.2%, P=0.001). The risk for incident DM was significantly higher in the hypertensive group compared with that in the normotensive group (OR 3.41 vs. 1.00, P<0.0001). However, the significance disappeared after making adjustments for the baseline BMI and fasting glucose levels (OR 1.18 vs. 1.00, P=0.83). We found that the significance of high BP in predicting incident DM was influenced by the baseline BMI and fasting glucose levels of the subjects.

Insulin resistance and cardiovascular disease risk factors in subjects with prehypertension

Prehypertension is considered to be associated with increased cardiovascular disease (CVD), and some data suggest that insulin resistance is common in this group. The goal of this study was to quantify insulin action by determining the steady-state plasma glucose (SSPG) concentration during the insulin suppression test in apparently healthy individuals with prehypertension (n=126) and to elucidate the relationship between insulin action and CVD risk.We found a marked heterogeneity in insulin sensitivity in the prehypertension group, and when we divided the population into insulin-sensitive, insulin-resistant and intermediate groups, there were significant (p<0.01) increases in plasma glucose and triglyceride concentrations and decreases in high-density lipoprotein cholesterol concentrations with progressive degrees of insulin resistance. These data show that at least one-third of patients with prehypertension are insulin resistant, display the accompanying metabolic abnormalities, and merit enhanced surveillance and intensive efforts at therapeutic intervention to prevent CVD.

Hypertension, obesity, and inflammation: the complex designs of a deadly trio

Hypertension is a powerful risk factor for cardiovascular disease and frequently occurs in conjunction with obesity and the metabolic syndrome. Recent research into the underlying pathophysiologic processes common to these entities has uncovered the role of a heightened inflammatory state signified by a host of circulating biocytokines. Systemic and local hormonal effectors, such as angiotensin II and aldosterone, interact with inflammatory and oxidative stress to augment endothelial damage in a complex manner. The kidneys play a prominent role in the renin-angiotensin cascade and the abnormal pressor response that ensues. Insulin resistance underlies the pathogenesis of obesity and the metabolic syndrome. The interplay of hypertension, insulin resistance, and obesity vastly enhances the noxious influence of inflammation on the vasculature, promoting deleterious immune adaptations and ultimately increasing atherosclerotic risk. Although certain classes of available pharmacologic agents already address the altered endovascular and humoral dynamics in hypertension, a better understanding of the proinflammatory picture holds promise of targeted treatment modalities in future.

Positive relationship between plasma leptin level and hypertension

Leptin is an adipose tissue-derived hormone shown to be related to metabolic, inflammatory, and hemostatic factors involved in hypertension development. Animal studies suggest that higher leptin levels may activate the sympathetic nervous system and cause elevations in blood pressure (BP). However, few studies have examined the association between leptin and hypertension in humans. Also it is not clear whether this association is present among women as well as men. Therefore, we examined the association between plasma leptin levels and hypertension in a representative sample of US adults. We examined the third National Health and Nutrition Examination Survey participants >20 years of age (n=5599; 54.7% women). Plasma leptin levels were categorized into quartiles (women: <7.68, 7.68 to 13.18, 13.19 to 21.70, >21.70 fg/L; men: <2.64, 2.64 to 4.36, 4.37 to 7.12, >7.12 fg/L). Hypertension was defined as BP-reducing medication use or having systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg. We found that higher plasma leptin levels were positively associated with hypertension after adjusting for age, sex, race/ethnicity, education, smoking, alcohol intake, body mass index, diabetes mellitus, serum cholesterol, and C-reactive protein. Compared with quartile 1 of leptin (referent), the odds ratio (95% CI) of hypertension associated with quartile 4 was 1.89 (1.24 to 2.09; P for trend=0.0036). Subgroup analyses examining the relation between leptin and hypertension by sex and body mass index categories also showed a consistent positive association. In conclusion, higher plasma leptin levels are associated with hypertension both among women as well as men in a representative sample of US adults.