Mean arterial blood pressure and serum levels of the molar ratio of insulin-like growth factor-1 to its binding protein-3 in healthy centenarians

Plasma insulin-like growth factor-1 level and risk of incident hypertension in nondiabetic women

BACKGROUND

Insulin-like growth factor-1 may be involved in regulation of blood pressure through multiple pathways; however, the prospective association between plasma insulin-like growth factor-1 level and risk of hypertension has never been explored.

METHODS

We prospectively examined the association between plasma insulin-like growth factor-1 level and the risk of incident hypertension among 2046 women without a history of hypertension or diabetes. Cox proportional hazards regression models were used to adjust for potential confounders.

RESULTS

We identified 181 incident cases of hypertension during 4 years of follow-up. After adjusting for plasma insulin-like growth factor binding protein-3 level and other potential confounders, women in the top tertile of insulin-like growth factor-1 had decreased risk of incident hypertension (relative risk 0.56, 95% confidence interval 0.35-0.91) compared with women in the bottom tertile. After further adjusting for C-peptide level and C-reactive protein level in subsets of participants who also had those markers measured, the association between insulin-like growth factor-1 and risk of incident hypertension remained robust.

CONCLUSIONS

Higher circulating insulin-like growth factor-1 level is associated with a decreased risk of incident hypertension among nondiabetic women.

Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowers

BACKGROUND

The intensive physical activity is often associated with cardiac changes.

OBJECTIVES

(i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters.

METHODS

Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PS(m)), systolic (S(m)), the ratio of early diastolic (E(m)) to atrial (A(m)) velocities as well as myocardial time intervals were calculated.

RESULTS

Rowers had higher serum IGF-I levels (P = 0.04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0.50, P = 0.03), RV PS(m) velocity (r = 0.55, P = 0.01) and with RV myocardial precontraction time (r = -0.57, P = 0.01). These associations remained significant after adjusting for age and heart rate.

CONCLUSIONS

Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PS(m) velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis.

Hypertension in acromegaly and in the normal population: prevalence and determinants

BACKGROUND

The GH/IGF-I axis has a relevant role to play in the cardiovascular system but its implication in the pathogenesis of hypertension in the normal population and in acromegaly is not yet clear.

PATIENTS AND MEASUREMENTS

The aim of this retrospective and controlled study was to evaluate the prevalence and determinants of hypertension in 200 patients with acromegaly and 200 nonacromegalic subjects, matched for sex, age, body mass index (BMI) and smoking habits.

RESULTS

Hypertension was found in 46% of patients and in 25% of controls (P < 0.0001), without any difference between men and women. Family history of hypertension occurred in 30% of hypertensive acromegalic patients and in 62% of hypertensive controls (P < 0.0001). In both groups, hypertensive subjects were older than normotensive subjects. Systolic (SBP) and diastolic blood pressures (DBP) in hypertensive acromegalic patients were lower and higher, respectively, than in hypertensive controls. The risk of hypertension increased with age and was higher in the patients than in the controls [hazard ratio (HR) 1.9; P = 0.0002]. Independent predictors of SBP were age and glucose in the acromegalic population, and BMI, age and glucose levels in the controls. Independent predictors of DBP were age and glucose in the patients, and BMI, age and IGF-I in the controls.

CONCLUSIONS

In acromegaly, hypertension is more frequent than in the general population, involves predominantly DBP, and occurs earlier, is not related to gender, and is less frequently related to family history of hypertension and IGF-I levels. IGF-I may have a protective role for DBP in the general population.

Cardiorenal protective effects of vasopeptidase inhibition with omapatrilat in hypertensive transgenic (mREN-2)27 rats

Vasopeptidase inhibitors simultaneously inhibit both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The aim of this study was to determine the cardiorenal effects of the vasopeptidase inhibitor omapatrilat in the transgenic m(Ren-2)27 rat which exhibits fulminant hypertension and severe organ pathology. At 6 weeks of age, male Ren-2 rats were randomized to receive no treatment (N = 10), the ACE inhibitor fosinopril 10 mg/kg/day (N = 10), or omapatrilat 10 mg/kg/day (N = 10) or 40 mg/kg/day (N = 10) by daily gavage for 24 weeks. Various cardiorenal functional and structural parameters were assessed. Compared to controls, all treatment groups reduced hypertension in control Ren-2 rats, with both doses of omapatrilat reducing systolic blood pressure significantly more than fosinopril (control, 178 +/- 3 mmHg; fosinopril 10 mg/kg/day, 130 +/- 4 mmHg; omapatrilat 10 mg/kg/day, 110 +/- 3 mmHg; omapatrilat 40 mg/kg/day, 91 +/- 3 mmHg). Omapatrilat dose-dependently reduced cardiac hypertrophy, caused a greater inhibition of renal ACE than fosinopril, and was the only treatment to inhibit renal NEP. Attenuation of albuminuria, glomerulosclerosis and cardiorenal fibrosis occurred to a similar degree with omapatrilat and fosinopril. Omapatrilat confers cardiorenal protection in the hypertensive Ren-2 rat. Although inhibition of tissue NEP may contribute to the superior blood pressure reduction by omapatrilat, overall, the results are consistent with the central role that angiotensin II plays in renal and cardiac fibrosis in this model of hypertension.

More favorable midlife cardiovascular risk factor levels in male twins and mortality after 25 years of follow-up is related to longevity of their parents

BACKGROUND

Genetic studies of life span in humans have used broad survival measures, most commonly longevity, which is moderately correlated between parents and offspring. We examined whether genetic cardiovascular disease risk factors in male twin offspring are related to longevity of their parents in the National Heart, Lung, and Blood Institute twin study.

METHODS

Cholesterol levels, body mass index, blood pressures, and pulmonary function measured over the first three examinations (average subject age 48, 58, and 63 years, respectively) were compared with the twins' paternal, maternal, and parental mean longevity divided into upper versus lower quintiles. The presence of an apolipoprotein E epsilon 4 allele typed from DNA collected at Exam 3 and mortality in the twin cohort through 1997 were also examined in relation to parental longevity quintiles.

RESULTS

Twins, particularly whose fathers died at younger ages, had significantly higher total cholesterol (p <.05), ratio of total cholesterol to high-density lipoprotein (p <.01), and blood pressures (p <.01) in middle age. This relationship decreased at the subsequent two examinations, but consistently, twins with longer-lived parents tended to have better risk factor profiles. A twin death (mean age 65) was significantly more common in families with mothers (p <.001) and, to a lesser extent, fathers who died early. An apolipoprotein epsilon 4 allele was more common in families with parents' age at death in the lowest quintile (p <.05).

CONCLUSIONS

Systolic blood pressures, cholesterol levels, and the presence of the apolipoprotein E epsilon 4 allele likely contribute to the observed familial correlations in longevity that have been reported in the literature.

Elevated plasma activator inhibitor 1 is not related to insulin resistance and to gene polymorphism in healthy centenarians

Previous studies demonstrated a relationship between the degree of insulin resistance and plasma plasminogen activator inhibitor type-1 (PAI-1) levels. We aim at investigating the relationship between the degree of insulin resistance and plasma PAI-1 levels in aged subjects (n=83) and in healthy centenarians (n=42). In all subjects the degree of insulin resistance was assessed by HOMA method. Our data demonstrated that healthy centenarians have higher plasma PAI-1 levels (73.1+/-13.9 vs 23.7+/-14.7 ng/ml, P<0.001) and lower degree of insulin resistance (1.4+/-0.5 vs 3.3+/-1.3, P<0.001) than aged subjects. In aged subjects plasma PAI-1 levels correlated with the degree of insulin resistance (r=0.61, P<0.001), fasting plasma triglycerides (r=0.74, P<0.001) and age (r=0.33, P<0.001). All such associations were lost in centenarians. Plasma PAI-1 Ag levels were also similar in aged subjects and centenarians even after categorization for PAI gene polymorphism. In multivariate analysis, a model made by age, sex, body mass index, fasting plasma triglycerides, HOMA and PAI-1 gene explained 65 and 50% of plasma PAI-1 level variations in aged subjects and centenarians, respectively. Nevertheless, HOMA (P<0.001) was significantly and independently associated with plasma PAI-1 levels only in aged subjects. In conclusion, our data demonstrates that in healthy centenarians, plasma PAI-1 were not associated with the degree of insulin resistance as in aged subjects. Frequency of PAI-1 genotype does not provide an explanation for such differences between aged subjects and centenarians.

Omapatrilat versus lisinopril: efficacy and neurohormonal profile in salt-sensitive hypertensive patients

Omapatrilat, a vasopeptidase inhibitor, simultaneously inhibits neutral endopeptidase and ACE. The efficacy and hormonal profile of omapatrilat and lisinopril were compared in salt-sensitive hypertensive patients. On enrollment, antihypertensive medications were withdrawn, and patients received a single-blind placebo. On day 15, salt-sensitivity determinations were made. Salt-sensitive hypertensive patients returned within 5 to 10 days for baseline evaluations of ambulatory diastolic blood pressure, ambulatory systolic blood pressure, and atrial natriuretic peptide. Salt-sensitive hypertensive patients were randomized to receive double-blind omapatrilat (n=28) or lisinopril (n=33) at initial doses of 10 mg for 1 week, increasing to 40 and 20 mg, respectively, for an additional 3 weeks. Ambulatory blood pressure and urinary atrial natriuretic peptide were assessed at study termination. Both omapatrilat and lisinopril significantly reduced mean 24-hour ambulatory diastolic and systolic blood pressures; however, omapatrilat produced significantly greater reductions in mean 24-hour ambulatory diastolic blood pressure (P=0.008), ambulatory systolic blood pressure (P=0.004), and ambulatory mean arterial pressure (P=0.005) compared with values from lisinopril. Both drugs potently inhibited ACE over 24 hours. Omapatrilat significantly (P<0.001) increased urinary excretion of atrial natriuretic peptide over 0- to 24-hour (3.8-fold) and 12- to 24-hour (2-fold) intervals; lisinopril produced no change. Omapatrilat significantly (P<0.001) increased urinary excretion of cGMP over the 0- to 24- and 4- to 8-hour intervals compared with that from lisinopril. Neither drug had a diuretic, natriuretic, or kaliuretic effect. In conclusion, in salt-sensitive hypertensive patients, omapatrilat demonstrated the hormonal profile of a vasopeptidase inhibitor and lowered ambulatory diastolic and systolic blood pressures more than lisinopril.

Vasopeptidase inhibitors, neutral endopeptidase inhibitors, and dual inhibitors of angiotensin-converting enzyme and neutral endopeptidase

Vasopeptidase inhibitors represent a new class of cardiovascular drugs. They function as a combined angiotensin-converting enzyme (ACE) inhibitor and neutral endopeptidase (NEP) inhibitor, the latter of which potentiates the actions of atrial natriuretic peptide (ANP) by minimizing its degradation in the circulation. The consequence of such dual inhibition is a synergistic reduction of vasoconstriction and enhancement of vasodilation, thereby serving to more effectively reduce blood pressure. Furthermore, inhibition of the renin-angiotensin-aldosterone system (RAAS) prevents physiologic compensatory responses in vivo seen with NEP inhibition alone. Vasopeptidase inhibitors have also shown to potentiate bradykinin and adrenomedullin, which additionally contribute to cardiovascular regulation. The most extensively researched and promising agents within the class of VP inhibitors is omapatrilat, a mercaptoacyl derivative of a bicyclic thiazepinone dipeptide. It is a single molecule with equal potency and affinity for ACE and NEP inhibition. Although ACE inhibition tends to more selectively benefit high-renin models of hypertension, vasopeptidase inhibition has been shown to be equally efficacious in low-, normal-, and high-renin models. Contrary to NEP inhibition alone, omapatrilat has also demonstrated the ability to significantly reduce blood pressure in spontaneously hypertensive rats, the equivalent of essential hypertension in humans. Studies also suggest that omapatrilat has cardioprotective properties, especially in the setting of congestive heart failure. More specifically, animal models have demonstrated omapatrilat to be more effective than ACE inhibition alone in remodeling the heart and improving its contractile function. Human studies have documented the efficacy of omapatrilat in the treatment of both hypertension and, to a lesser extent, heart failure. Safety concerns (specifically angioedema) are currently being addressed before the widespread utilization of this promising new agent.

Healthy centenarians do not exist, but autonomous centenarians do: a population-based study of morbidity among Danish centenarians

OBJECTIVE

To assess the prevalence of common illnesses in an unselected population of centenarians.

DESIGN

A population-based survey.

SETTING

Denmark.

PARTICIPANTS

All Danes who celebrated their 100th anniversary between April 1, 1995 and May 31, 1996: 276 persons.

MEASUREMENTS

All participants (including proxies) were visited at their domicile for an interview (sociodemographic characteristics, activities of daily living, living conditions, need of assistance from other people, former health and current diseases, current medication) and a clinical examination (dementia screening test, heart and lung auscultation, neurological assessment, height and weight, electrocardiogram, arm and ankle blood pressure, assessment of hearing and vision capacity, a short physical performance test, bio-impedance, lung function test, blood test). Further health information was retrieved from medical files and national health registers.

RESULTS

Seventy-five percent (207) of eligible subjects participated in the study. Cardiovascular disease was present in 149 (72%) subjects. Osteoarthritis (major joints) was present in 54%, hypertension (> or =140/ > or =90) in 52%, dementia in 51%, and ischemic heart disease in 28%. The mean number of illness was 4.3 (standard deviation (SD) 1.86). Only one subject was identified as being free from any chronic condition or illness. Sixty percent had been treated for illness with high mortality. In 25 autonomous (nondemented, functioning well physically, living at home) and 182 nonautonomous centenarians, comorbidities were equivalent.

CONCLUSION

Because they have a high prevalence of several common diseases and chronic conditions, Danish centenarians are not healthy. However, a minor proportion was identified as being cognitively intact and functioning well.

Metabolic age modelling: the lesson from centenarians

Evolutionary theories of ageing, and data emerging from cellular and molecular biology of ageing, suggested that animals and humans capable of reaching an age close to the extreme limit of the life span should be equipped with a very efficient network of anti-ageing mechanisms. Indeed several evidences have demonstrated that starting from young to very old subjects, ageing is associated with a progressive remodelling. Thus, a new paradigm, the remodelling theory of age, was proposed. This theory, focusing on the human immune system, suggested that immunosenescence is the net result of the continuous adaptation of the body to the deteriorative changes occurring over time. According to this hypothesis, body resources are continuously optimized, and immunosenescence must be considered a very dynamic process including both loss and gain. Whether the metabolic pathways and the endocrine functions are also part of the age remodelling is not investigated. The aim of this review is to focus on the age-related changes in metabolic pathways and endocrine functions and to demonstrate that healthy centenarians (HC) represent the best living example of successful age-remodelling in whom the age remodelling has occurred without problems. In order to design the clinical picture of such successful ageing, anthropometric, endocrine and metabolic characteristics of healthy centenarians (HC), compared with aged subject, have been outlined.

Reversal of cardiac hypertrophy and fibrosis by S21402, a dual inhibitor of neutral endopeptidase and angiotensin converting enzyme in SHRs

OBJECTIVE

The major advantage of dual inhibitors of neutral endopeptidase (NEP) and angiotensin converting enzyme (ACE) is their ability to lower blood pressure irrespective of renin or volume status. The aim of this study was to determine whether dual NEP/ACE inhibition produces different effects on cardiovascular structure and fibrosis, hormonal parameters and inhibition of tissue enzymes compared with selective inhibition of ACE and NEP in the spontaneously hypertensive rat (SHR).

METHODS

Male SHRs received the dual NEP/ACE inhibitor (S21402, 100 mg/kg per day), the ACE inhibitor (captopril, 50 mg/kg per day), the NEP inhibitor (SCH42495, 60 mg/kg per day) or vehicle for 2 weeks.

RESULTS

S21402 produced equivalent blood pressure lowering effects to captopril (vehicle, 220 +/- 1 mmHg; S21402, 189 +/- 2 mmHg; captopril, 187 +/- 3 mmHg), but was a more effective antihypertensive agent than SCH42495 (214 +/- 2 mmHg, P< 0.01). All treatments reduced left ventricular mass (P< 0.05) and cardiac fibrosis (P< 0.01). S21402 inhibited renal NEP and ACE (P< 0.01), SCH42495 inhibited renal NEP (P < 0.01), and captopril inhibited renal ACE (P< 0.01). Captopril and S21402 increased plasma renin activity (P< 0.05), but the rise with S21402 was attenuated compared with that caused by captopril (P< 0.01). All treatments reduced plasma aldosterone levels (P< 0.01), and NEP inhibition with SCH42495 and S21402 increased plasma atrial natriuretic peptide (ANP; P< 0.05).

CONCLUSIONS

These results indicate that selective NEP inhibition has major benefits in the regression of cardiac hypertrophy and reduction of fibrosis but has limited antihypertensive effects. The dual NEP/ACE inhibitor S21402 offered no advantage over the selective ACE inhibitor in terms of blood pressure reduction, or attenuation of cardiac hypertrophy and fibrosis, but did increase plasma ANP and blunted the reactive rise in renin with ACE inhibition. Further studies are needed to determine whether more complete blockade of the renin-angiotensin system with dual NEP/ACE inhibition results in additional benefits in terms of morbidity and mortality in cardiovascular disease.