Cases analysis of rational use of medicine (48) Hypertension with insulin resistance

1.ClinicalNotes

48-year-old male

Obesity,BMI:30 kg/m2

Waist circumference:110 cm

Bp:150/105 mmHg

TG:1.85 mmol/L

TC:6.5 mmol/L

FPG:6.8 mmol/L

Diagnosis:Hypertension with insulin resistance,Dyslipidemia,Impaired fasting glucose(IFG)

2.Drugadministration

Cap Valsartan 80 mg qd

Tab Rosiglitazone maleate 4 mg qd

3.Analysis

(1)Obesity,Body Fat Distribution and Hypertension

Obesity in clinical and epidemiological studies is most often assessed by body mass index (BMI，Weight divided by height squared).By difinition of WHO,BMI≥25 kg/m2is overweight,BMI≥30 kg/m2is obesity.Obesity is widely recognized as a risk factor for the development of hypertension.Conversely,weight loss has been shown to be associated with decreases in BP in many studies.Recently,the way body fat is distributed has been recognized as a major risk factor,with upper-body or central obesity being associated with dyslipidemia,Type Ⅱ-diabetes mellitus,and hypertension.The most common clinical and epidemiological assessments of central obesity have been made using measures of waist circumference or the ratio of waist to hip circumferences (WHR).As standards as to what constitutes central obesity,some authors have suggested WHR>0.95 in men or >0.85 in women.In China,waist circumference ≥90 cm in men,or≥85 cm in women is considered as central obesity.The association between body fat distribution and blood pressure has been shown to be independent of obesity in a number of studies.An adverse body fat distribution has been associated with insulin resistance,which may be an important cause of hypertension.

(2)Insulin Resistance and Hypertension

Insulin resistance is defined as a reduction in insulin mediation of glucose uptake and metabolism in adipose tissue,skeletal muscle,and liver.Its etiology can be multifactorial and includes alterations in the insulin receptor or several postreceptor sites.

Substantial clinical information shows a relation between obesity,insulin resistance,hyperinsulinemia and essential hypertension.Other variable associated with insulin resistance and hyperinsulinemia includes dyslipidemia,especially high triglyceride levels and low high-density lipoprotein cholesterol levels,and glucose intolerance.Insulin resistance may underlie the cluster of atherogenic changes.Multiple mechanisms have been proposed to explain a possible relationship between insulin resistance and hypertension,including increased sympathetic nervous system activity,damaged vascular endothelia,decreased production of NO of dilating blood vessels,proliferation of vascular smooth muscle cells,altered cation transport and increased sodium transport.

(3)Nonpharmacological and pharmacological therapy．

The goal of antihypertensive therapy is to reduce cardiovascular morbidity and mortality and to prolong useful life by the least intrusive means possible.This implies that quality of life is an important consideration in tailoring the regimen for a given patient.On the other hand,hypertension and other risk factors should always be controlled simultaneously to win a good effect on a patient's quality of life.Stopping smoking,reducing weight,moderating alcohol consumption,and regular physical exercise are very necessary to prevent strokes and heart attacks.

ACEIs and ARBs have protections of kidney and heart,enhance insulin sensitivity and relax insulin resistance.Some studies showed ARBs,such Valsartan,Irbesartan,have advantage of improving impaired glucose tolerance (IGT),preventing the development of diabetes.CCBs do not affect insulin sensitivity.Insulin-sensitizing agents,such Metformin HCl,Rosiglitazone maleate,increase insulin sensitivity,improve insulin resistance and have antihypertensive effects.

Antihypertensive agents that worsen insulin sensitivity might be expected to increase the risk of diabetes because hyperinsulinemia and insulin resistance are strongly related to the incidence of T2DM.Thiazide diuretics(especially at large dose )and β-blockers might worsen glucose tolerance and insulin resistance,We cannot be too careful in prescribing them for hypertensive subjects with insulin resistance or diabetes.