mmHg In Males Research Articles

Intraocular pressure and Schirmer tear test results in clinically normal Long‐Eared Hedgehogs (Hemiechinus auritus): reference values

The present study was undertaken to establish reference values for Schirmer tear test (STT) and intraocular pressure (IOP) in the long-eared hedgehog (Hemiechinus auritus). Fourteen healthy long-eared hedgehogs (H. auritus) of either sex were studied. The hedgehogs were individually immobilized with an intramuscular injection of combined Ketamine (20 mg/kg) and Diazepam (0.5 mg/kg), and each animal underwent ophthalmic examinations including: STT, tonometry, biomicroscopy, and indirect ophthalmoscopy. No significant effects of animal gender, weight, side (right vs. left eye) were found in this study. Mean (SD) STT values for all eyes (n = 28) were 1.7 ± 1.2 mm/1 min with a range of 0-4 mm/1 min. Mean STT in male animals was 2.2 ± 1.2. Mean STT in female Hedgehogs was 1.3 ± 1.1. Mean (SD) IOP values by applanation tonometry were 20.1 ± 4.0 mmHg (range 11.5-26.5 mmHg). Mean (SD) IOP values by applanation tonometry were 18.2 ± 4.0 and 22.0 ± 3.2 mmHg for males and females, respectively. This study reports STT and IOP findings in long-eared hedgehogs (H. auritus).

Efficacy of an olmesartan medoxomil-based treatment algorithm in patients with hypertension and type 2 diabetes: analysis of diurnal blood pressure control as assessed by 24-hour ambulatory blood pressure monitoring

Secondary, prespecified analysis of a single-arm, open-label study evaluating the efficacy of olmesartan medoxomil (OM) plus hydrochlorothiazide (HCTZ) in patients with hypertension and type 2 diabetes. After placebo run-in, 192 patients received OM 20 mg/day for 3 weeks. If blood pressure (BP) remained ≥120/70 mmHg, patients were uptitrated every 3 weeks to OM 40 mg/day, OM/HCTZ 40/12.5 mg/day, and OM/HCTZ 40/25 mg/day. Efficacy was evaluated by 24-hour ambulatory BP monitoring. Secondary endpoints included changes in ambulatory systolic BP (SBP) and diastolic BP (DBP) during daytime (08:00 to 16:00) and nighttime (22:00 to 06:00), as well as achievement of prespecified ambulatory BP targets in the total cohort and subgroups based on gender, race, hypertension severity, and age (≥65 or <65 years). Dipper status (nocturnal decrease in BP ≥10% of mean daytime BP) was assessed. At baseline, mean ambulatory BP was 151.2 ± 12.7/87.6 ± 9.0 mmHg during the daytime and 140.3 ± 13.1/78.1 ± 8.6 mmHg during the nighttime. Mean daytime and nighttime ambulatory BP was reduced from baseline by 22.3 ± 13.7/12.0 ± 8.9 mmHg and 18.8 ± 12.4/ 10.2 ± 7.2 mmHg, respectively. The reduction in daytime ambulatory SBP was 24.4 ± 11.8 mmHg in Blacks, 21.7 ± 14.2 mmHg in non-Blacks, 23.6 ± 12.3 mmHg in females, 21.2 ± 14.8 mmHg in males, 23.4 ± 11.6 mmHg in patients aged ≥65 years, and 21.9 ± 14.4 mmHg in those aged <65 years. Ambulatory BP targets of <130/80, <125/75, and <120/80 mmHg were reached by 51.7%, 36.0%, and 32.6% of patients during the daytime and 69.8%, 60.5%, and 50.6% of patients during the nighttime. After 12 weeks of treatment, 36.4% of baseline nondippers converted to dippers. OM ± HCTZ effectively lowered ambulatory BP in patients with type 2 diabetes and hypertension, enabling them to achieve ambulatory BP targets during both the daytime and nighttime.

Relationship between the converting ability of liver microsomes and monocrotaline-induced pulmonary hypertension in male, female and castrated male rats

It is well known that the initial reaction of monocrotaline-induced pulmonary hypertension in rats (MPH) is injury to the endothelial cells of pulmonary vascular bed by monocrotaline-pyrrole (MP), which is converted from monocrotaline (M) by cytochrome P450 monooxygenase in hepatic microsomes. It is also known that the degree of MPH differs between sexes. The mechanisms of MPH remain, however, to be elucidated. The purpose of this study is to clarify the relationship between the converting ability of hepatic microsomes and the sexual difference in MPH using castrated male rats. A 40 mg/kg dose of M was given to fifteen 6 week-old male, twelve 6 week-old female and fifteen 6 week-old castrated male, Sprague-Dawley, rats. The castration was done at three weeks of age. Four weeks after M administration, the right ventricular systolic pressure (RVSP) and the right ventricular to total ventricular weight ratio (RV/T) were measured as indices of pulmonary hypertension. Livers were taken from six 6 week-old male, six, 6 week-old female and six 6 week-old castrated male, Sprague-Dawley, rats and then homogenized and centrifuged to extract hepatic microsomes. M, at 3.3 mM, was added to concentrated hepatic microsomes (0.25 to 1.5 mg/ml) in order to produce MP. The concentration of the MP was measured using a modification of Mattock's method. The mean value of RVSP was 86.5 mmHg in males, 59.6 mmHg in females and 73.9 mmHg in castrated males. The mean value of RV/T was 0.453 in males, 0.358 in females and 0.403 in castrated males.(ABSTRACT TRUNCATED AT 250 WORDS)

The relation between serum parathyroid hormone (PTH) and blood pressure. The Tromsø study

The objective of the present cross-sectional epidemiological study from Tromsø, North Norway was to evaluate the relation between blood pressure and serum parathyroid hormone (PTH). 10419 subjects were invited to participate in the fifth Tromsø study and 8128 attended. 7954 subjects had serum PTH measured, and among these, information on blood pressure medication was available in 5841 subjects (2554 males) with serum calcium within the reference range 2.20-2.60 mmol/L. In a multiple linearregression model with age, BMI, serum calcium, serum creatinine, and smoking status as covariables, serum PTH was a significant and positive predictor of systolic and diastolic blood pressure in both genders. When dividing the cohort in PTH quartiles, and adjusting for age, BMI, serum calcium, and serum creatinine, the differences between the lowest and highest PTH quartile in systolic and diastolic blood pressure were 5.0 and 3.5 mmHg for males and 4.1 and 2.5 mmHg for females, respectively. In previous studies we have found serum PTH to be a positive predictor for future increase in blood pressure, and also that the association between serum PTH and blood pressure cannot alone be ascribed to a blood pressure induced increase in urinary calcium excretion. To further elucidate the relation between serum PTH and blood pressure, randomized clinical trials with calcium and/or vitamin D supplementation to subjects with increased serum PTH levels are needed

High Definition Oscillometry: a novel technique for non‐invasive blood pressure monitoring in the cynomolgus monkey (Macaca fascicularis)

Current approaches for accurate blood pressure determination rely predominantly on invasive techniques. High Definition Oscillometry (HDO) was evaluated as a potential non-invasive approach for accurate blood pressure recordings in cynomolgus monkeys. In conscious animals, systolic, diastolic, mean arterial blood pressure (MAP) and pulse/minute were determined 15 times within approx. 9 minutes per individual. This session was performed during 3 consecutive days. Anaesthesia induced hypotension was controlled simultaneously with HDO and telemetry as reference. Repeated measurements were highly reproducible. After procedural habituation, mean MAP was 96.2 +/- 13.7 mmHg in males and 86.9 +/- 4.3 mmHg in females. Mean intraindividual coefficients of variation ranged between 10.8% and 2.4% depending on the session and parameter. Values determined by HDO corresponded to those reported for invasive techniques. Our results demonstrate, using telemetry as reference, the accuracy of HDO-based non-invasive blood pressure measurements in macaques to detect drug-related cardiovascular changes.

Descriptive epidemiology of blood pressure in a rural adult population in Northern Ghana

There are limited data on blood pressure (BP) levels in rural populations in sub-Saharan Africa. This is a cause for concern considering high BP contributes to a substantial public health burden in this population. Blood pressure levels were measured in a representative rural sample from Kassena-Nankana District of Northern Ghana, West Africa, and associations with anthropometric indices, age, sex, and time of BP measurement were assessed. This cross-sectional survey was made on a random sample drawn from a population register and included 207 males and 367 females aged between 18 and 65 years. Data collection consisted of anthropometric and blood pressure measurements after questionnaire interviews. Household salt consumption was also measured in 20 randomly selected households. Overall prevalence of casual high BP was 19.3% (111/574). Age-adjusted mean (standard deviation) systolic BPs (SBPs) and diastolic BPs (DBPs) were 124.25 (18.67) and 69.92 (12.09) mmHg in males and 122.07 (22.01) and 72.11 (12.35) mmHg in females. Mean body mass index (BMI) was 21.78 (3.09) kg/m2; 21.13 (2.27) for males and 22.15 (3.41) kg/m2 for females (p > 0.05). Blood pressures increased with age, 4 and 3 mmHg per decade for SBP and DBP, respectively (p < 0.000). Regression analyses showed that SBP was significantly associated with age, BMI, waist circumference and time of BP measurement (p < 0.000). In multiple regression analyses, age and BMI were independently associated with SBP and DBP in women (p < 0.001). Time of BP measurement was independently associated with SBP but only in men (p < 0.001). There was no increase in BMI with age. Repeat measurements in 89 subjects yielded a regression dilution factor of 0.57 for SBP. Salt consumption per individual was estimated as equivalent to 12.5 g of pure salt/day. Average BPs are not notably high in this predominantly lean rural West African population. Blood pressures do, however, increase as expected with age and BMI. Population-wide approaches need to be developed, appropriate to the level of medical provision, in order to address vascular disease risks resulting from higher than optimal BPs. These should include programs to reduce salt consumption.

Walking Activity, Body Composition and Blood Pressure in Adults with Intellectual Disabilities

Background Individuals with intellectual disabilities engage in limited physical activity which places their health at risk. This study examined the walking activity, body composition and blood pressure of adults with intellectual disabilities.Methods A group of male and female adults (n = 103) wore a pedometer for 7 days and were categorized into walking levels based on step counts. Measures of health variables were also taken.Results Mean blood pressure was 126/82 mmHg and 125/79 mmHg for males and females, respectively. Approximately 80% of the sample was overweight or obese. Most participants accumulated 5000–7999 steps/day while the fewest accumulated &gt;10 000 steps/day. Individuals who walked more did not have significantly lower blood pressure or healthier body composition.Conclusion The intensity of walking may have been inadequate for individuals in the higher walking levels to achieve health benefits. Furthermore, intake of high‐fat food may have contributed to blood pressure and body composition and countered the benefits of walking.

Blood pressure and its correlates in Tobagonian adolescents

To determine age-specific patterns and correlates of blood pressure (BP) in Tobagonian adolescents. Blood pressure, weight and heights were measured using standardized procedures. Age-height and gender-specific BP levels were established and compared with those established for adolescents in the United States of America, the United Kingdom and Jamaica. Of the available population, 3749 or 84.9% participated in the study. Among Tobagonian adolescents, the mean one-year age increment in systolic blood pressure (SBP) was 3.6 (95% CI: 3.2, 3.9) mmHg in males and 1.5 (95% CI: 1.2, 1.8) mmHg in females. Likewise, the mean one-year increment in diastolic blood pressure (DBP) was 2.1 (95% CI: 1.7, 2.4) mmHg in males and 1.2 (95% CI: 0.9, 1.4) mmHg in females. There was an inversion of mean BP with age. Females 12-13 years having significantly higher mean SBP while those 15-18 years had lower SBP than their male counterparts. Similarly, females 12-14 years had significantly higher mean DBP while those 16-18 years had lower DBP than their male counterparts. Approximately, 6.1% (95% CI: 5.4, 7.0) and 8.2% (95% CI: 7.4, 9.1) of participants had elevated SBP and DBP based on the US reference standards. Adolescents from the UK had average SBP and DBP that were 10 mmHg higher and lower respectively than their Tobagonian counterparts while Jamaican adolescents had diastolic BP consistently lower than Tobagonian adolescents of similar age. Elevated BP was associated with overweight and family history of hypertension. Growth and maturational factors are important determinants of blood pressure levels in this population. Furthermore, the wide variation in these key variables among possible BP referent populations necessitates the development of local blood pressure reference standards for Tobagonian adolescent populations.

Male Gender and Not the Severity of Hypertension Is Associated With End-Organ Damage in Aged Stroke-Prone Spontaneously Hypertensive Rats

It is well-known that gender affects the progression of kidney failure. Male patients exhibit faster development of age-dependent renal disease than do women. In the present study, we examined arterial blood pressure (BP), proteinuria, and end-organ damage in male and female retired breeders from our colony of stroke-prone spontaneously hypertensive rats (SHRSP). Male (n = 7) and female (n = 11) SHRSP littermates maintained on Purina Laboratory Chow 5008 and water were studied starting at 53 weeks of age. Systolic BP was measured by tail-cuff plethysmography and 24-h urinary protein excretion was quantified while animals were housed in metabolic cages. Blood was obtained by retro-orbital bleeding. Mean arterial pressure (MAP) was then monitored by radiotelemetry. Organs were preserved for histopathologic assessment. Tail-cuff systolic BP did not differ between the sexes. Male SHRSP exhibited greater proteinuria (128 +/- 7 mg/d) than females (21 +/- 5 mg/d, P < .001). Blood urea nitrogen was higher in males (22 +/- 2 mg%) v females (15 +/- 1 mg%, P < .005). The MAP by radiotelemetry did not differ between the sexes (179 +/- 3 mm Hg in males v 192 +/- 6 mm Hg in females, 2 weeks after probe implantation). Stroke-related mortality was greater in males (83%) than females (10%). Renal vascular disease including thrombotic microangiopathy affecting glomeruli and microvessels and cardiac damage were more prominent in male SHRSP. These findings demonstrate that male gender is a major risk factor for multisystem end-organ damage associated with aging and hypertension in SHRSP, despite comparable degrees of hypertension among males and females.

Serum albumin and blood pressure: a population-based, cross-sectional study

Information about the association between serum albumin and blood pressure is limited. The purpose of the present paper was to investigate this relationship in different age groups in males and females. In the cross-sectional Norwegian Oslo Health Study, the concentration of serum albumin and blood pressure was determined in 5071 men and women 30-75 years of age. The albumin-blood pressure relationship was studied using multiple regression. In general, men had higher albumin values than women, and young subjects had higher albumin values than old. Within all age groups and in both sexes, systolic and diastolic blood pressure increased with increasing albumin concentration within the physiological range. An increase in the albumin concentration over the physiological range from approximately 40 to 50 g/l was associated with an increase in the systolic blood pressure between 5 and 11 mmHg in males, depending on age, and between 6 and 17 mmHg in females. Corresponding increases in diastolic blood pressure were between 3 and 7 mmHg in males, and 4 to 9 mmHg in females. Per one SD increment in the albumin concentration the blood pressure increase was 1-3 mmHg. Within the different age groups, irrespective of sex and age, a positive association was found between serum albumin and blood pressure. Since albumin, in contrast to high blood pressure, is considered to be cardioprotective, the two variables probably affect cardiovascular risk by unrelated mechanisms.

Relation Between Intraocular Pressure and Systemic Health Parameters in Taiwan

The aim of the study was to evaluate the association between intraocular pressure (IOP) and several systemic health parameters in Taiwan. We retrospectively reviewed the medical records from all participants who had been examined in China Medical University Hospital. A total of 1,271 subjects (mean age, 50.0 +/- 12.0 years; age range, 21 to 85) who had not undergone any medical treatment for ocular hypertension or glaucoma were included in this study. Systemic factors (age, sex, blood pressure, total cholesterol, triglycerides, fasting glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, body mass index, waist circumference) were measured. One-way analysis of variance, Pearson correlation coefficients, and multivariate linear regression were used. There were 674 (53.0%) males and 597 (47.0%) females in this study. After controlling for the other covariates, the multivariate linear regression analysis showed that in males and females, systolic blood pressure was positively associated with IOP. That is, a change in systolic blood pressure by 1 mm Hg would alter the measured IOP by 0.024 mm Hg in males (95% CI, 0.002, 0.046; P = 0.031) and 0.030 mm Hg in females (95% CI, 0.006, 0.053; P = 0.014). In males, age was inversely associated with IOP. That is, a change in age by 1 year would alter the measured IOP by -0.039 mm Hg (95% CI, -0.059, -0.020; P = 0.0001). IOP was found to have a strong positive association with systolic blood pressure in males and females. IOP was inversely associated with age in males. This study may provide basic information for further studies on IOP in Taiwan.

Respiratory muscle dysfunction in idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a pulmonary vasculopathy of unknown aetiology. Dyspnoea, peripheral airway obstruction and inefficient ventilation are common in IPAH. Data on respiratory muscle function are lacking. This prospective single-centre study included 26 female and 11 male patients with IPAH in World Health Organization functional classes II-IV. Mean+/-SD pulmonary artery pressure was 48.6+/-16.9 in females and 53.1+/-22.9 mmHg in males; cardiac output was 3.7+/-1.3 and 4.2+/-1.7 L x min(-1). Maximal inspiratory pressure (PI,max) was lower in the female patients than in 20 controls (5.3+/-2.0 versus 8.2+/-2.0 kPa). In the male patients, PI,max was lower than in 25 controls (6.8+/-2.2 versus 10.5+/-3.7 kPa). Maximal expiratory pressure (PE,max) was lower in the female patients than in controls (6.2+/-2.6 versus 9.5+/-2.1 kPa), and in male patients as compared to controls (7.1+/-1.6 versus 10.3+/-3.9 kPa). There was no correlation between PI,max or PE,max and parameters of pulmonary haemodynamics or exercise testing. The ratio of mouth occlusion pressure within the first 0.1 s of inspiration and PI,max was higher in IPAH than in controls (females 0.067+/-0.066 versus 0.021+/-0.008; males 0.047+/-0.061 versus 0.023+/-0.016). In conclusion, this study provides the first evidence of inspiratory and expiratory muscle weakness in idiopathic pulmonary arterial hypertension. The pathomechanisms and the prognostic significance should be further investigated.

Blood pressure and adiposity in children and adolescents.

Although obesity is associated with important hemodynamic disturbances, there are few data on population-wide blood pressure (BP) distribution in children and adolescents in this era of endemic pediatric obesity. We conducted a school-based survey of a representative sample of youth aged 9, 13, and 16 years in Quebec, Canada. Resting BP was measured with an oscillometric device in 3589 subjects (80% response). Additional measures included height, weight, and subscapular and triceps skinfold thickness, an age-appropriate questionnaire, and a fasting blood draw. Mean (SD) systolic/diastolic BP (SBP/DBP) levels in 9-, 13-, and 16-year-olds were 103 (9)/57 (6), 113 (12)/58 (7), and 124 (14)/61 (7) mm Hg in males and 103 (10)/57 (6), 111 (11)/60 (7), and 114 (11)/62 (7) mm Hg in females. The prevalence of high-normal or elevated SBP was 12%, 22%, and 30% among 9-, 13-, and 16-year-old males, respectively, and 14%, 19%, and 17% among same-aged females. The prevalence of high-normal or elevated DBP was <1%. In multiple linear regression analysis, body mass index was consistently associated with SBP and DBP in all age-gender groups. Mean SBP and the prevalence of high-normal and elevated SBP are elevated in children and adolescents. Public policy, public health programs, and clinical preventive measures are urgently needed to address the obesity epidemic and its hemodynamic consequences.

Anesthetic and physiologic effects of tiletamine, zolazepam, ketamine, and xylazine combination (TKX) in feral cats undergoing surgical sterilization

Tiletamine (12.5 mg), zolazepam (12.5 mg), ketamine (20 mg), and xylazine (5 mg) (TKX; 0.25 ml, IM) combination was evaluated as an anesthetic in 22 male and 67 female adult feral cats undergoing sterilization at high-volume sterilization clinics. Cats were not intubated and breathed room air. Oxygen saturation (SpO 2), mean blood pressure (MBP), heart rate (HR), respiration rate (RR), and core body temperature were recorded. Yohimbine (0.25 ml, 0.5 mg, IV) was administered at the completion of surgery. TKX produced rapid onset of lateral recumbency (4±1 min) and surgical anesthesia of sufficient duration to complete surgical procedures in 92% of cats. SpO 2 measured via a lingual pulse oximeter probe averaged 92±3% in male cats and 90±4% in females. SpO 2 fell below 90% at least once in most cats. MBP measured by oscillometry averaged 136±30 mm Hg in males and 113±29 mm Hg in females. MBP increased at the onset of surgical stimulation suggesting incomplete anti-nociceptive properties. HR averaged 156±19 bpm, and RR averaged 18±8 bpm. Neither parameter varied between males and females or over time. Body temperature decreased significantly over time, declining to 38.0±0.8 °C at the time of reversal in males and 36.6±0.8 °C at the time of reversal in females. Time from anesthetic reversal to sternal recumbency was prolonged (72±42 min). Seven cats (8%) required an additional dose of TKX to maintain an adequate plane of anesthesia at the onset of surgery, and this was associated with significantly longer recovery times (108±24 min).

Endothelial dysfunction and alteration of nitric oxide/ cyclic GMP pathway in patients with exercise-induced hypertension.

The diagnostic and prognostic implication of exaggerated blood pressure response to exercise have been controversial, with opinions ranging from a benign process to a harbinger of potential cardiovascular morbidity. Endothelial dysfunction has been demonstrated in patients with atherosclerosis and as a risk factor for coronary artery disease. However, whether the cause of exercise-induced hypertension might be related to endothelial dysfunction has not been well elucidated. We evaluated endothelial function in patients who showed a systolic blood pressure > or = 210 mmHg in males and > or = 190 mmHg in females during treadmill exercise test. We measured the endothelial function of the brachial artery in 35 patients with exercise-induced hypertension, and in 35 age- and gender-matched normal control subjects, by a high resolution ultrasound technique, and the concentration of NO2-/NO3- and cyclic guanosine monophosphate (GMP). Endothelial-dependent vasodilation was impaired in patients with hypertension compared to normal controls (3.14 +/- 0.61 vs. 6.5 +/- 0.76%, p < 0.05). The extent of vasodilation was significantly correlated with age (r=-0.28, p < 0.05) and systolic blood pressure difference (r=-0.36, p < 0.05). The levels of NO2-/NO3- and cyclic GMP at maximal exercise were significantly higher than those at rest and recovery in both controls and the hypertensive group (p < 0.05). Although there was no significant difference in the increment of NO2-/NO3- during maximal exercise between the controls and hypertensive group (55 +/- 17 vs. 56 +/- 12 micro mol/L, p=NS), cyclic GMP level during maximal exercise was significantly higher in the control group than the hypertensive group (10 +/- 1.8 vs. 8.3 +/- 2.5 pmol/ml, p 0.05). Patients with exercise-induced hypertension have poor endothelium-dependent vasodilation due to an impaired nitric oxide/cyclic GMP pathway, which may play a significant role in increasing blood pressure during exercise with inadequate peripheral adjustment to changing cardiac output.

Prevalence and determinants of hypertension in an un-industrialised rural population of North India.

Recent studies have indicated a rising prevalence of hypertension in rural and urban areas of India. A population-based survey was carried out during 1994-1995 in seven rural and non-industrialised villages around RaipurRani block in the state of Haryana, India, to determine the prevalence of hypertension and its associated risk factors. A total of 2559 individuals (86% of the eligible population) in the 16 to 70-year age group were interviewed using a pre-tested structured questionnaire to find out the lifestyle characteristics. Three blood pressure (BP) readings were recorded with a random zero sphygmomanometer at three different times. One hundred and fourteen individuals (4.5%) were found to be hypertensive according to JNC V criteria (BP of > or = 140/90 mm Hg). Mean systolic and diastolic BPs were 116.9 and 71.7 mmHg in males and 119.1 and 72.7 mm Hg in female subjects respectively (P < 0.001). Females had significantly higher prevalence of hypertension than males (5.8% vs 3.0%, P < 0.05). Mean age of hypertensives (50.3 +/- 13.5 years) was higher than normotensives (34.9 +/- 14.5 years, P < 0.001). The prevalence of various risk factors among hypertensives as compared to normotensives were alcohol consumption (43.2% vs 23.1%, only among males, P < 0.001), higher economic status (P < 0.001) and smoking (43% vs 41.5%, P > 0.05). In addition hypertensives had higher mean weight (53.8 kg vs 48.4 kg, P < 0.001) and higher body mass index (21.5 vs 18.9 kg/m2, P < 0.001). Analysis showed that advancing age, sedentary lifestyle, higher alcohol consumption and higher body mass index are the risk factors for hypertension in the rural un-industrialised population of India.

Influence of food deprivation on sympathetic support of blood pressure in the spontaneously hypertensive rat

We examined the effects of short-term food deprivation on directly measured blood pressure and sympathetic support of blood pressure in male (n=7, 231±7 g) and female (n=9, 193±4 g) spontaneously hypertensive rats (SHR, Charles River). Carotid arterial catheters were inserted under halothane anesthesia for direct assessment of cardiovascular function in conscious, unrestrained rats. After several days of recovery, mean arterial blood pressure (MAP) and heart rate (HR) were determined prior to, during, and after food deprivation. Baseline MAP and HR were 170±14 mmHg and 351±13 beats/min in males and 187±6 mmHg and 354±9 beats/min in females. An overnight fast produced significant (P<0.05) reductions in MAP and HR. After 48-hours of food deprivation, MAP was markedly reduced in males (−42±7 mmHg) and in females (−42±9 mmHg). Heart rate was significantly decreased during fasting in both males (−76±10 beats/min) and females (−60±11 beats/min). Caloric deprivation was accompanied by a significant reduction in sympathetic support of blood pressure (−32±8 mmHg in males, −21±7 mmHg in females) as determined by the depressor response to ganglionic blockade produced by hexamethonium/atropine (30.0/0.1 mg/kg). After three days of refeeding, MAP, HR, and sympathetic support of blood pressure returned to values not significantly different from baseline. The results suggest that short-term food deprivation produces rapid reductions in MAP and HR in the SHR, which are mediated, at least in part, by reduced sympathetic tone.

Associations between lifestyle and cardiovascular risk factors in 18-year-old Australians

This study aimed to examine associations between cardiovascular risk factors and variables reflecting health-related behaviors in 18-year-old Australians. Anthropometry, blood pressure, nonfasting serum cholesterol, and physical fitness were measured in 301 male and 286 female Australian 18-year-olds. Usual physical activity, smoking, and drinking habits were assessed by questionnaire. Systolic (SBP), with mean SBP higher by 14 mm Hg in males, related positively to weight for height for age and "unsafe" drinking (exceeding Australian national guidelines) and negatively to fitness and birth weight. Total cholesterol, which was positively associated with waist-hip ratio and negatively with fitness, was higher in females [mean 4.4 mmol/L, 95% confidence interval (CI) 4.3, 4.5] than in males (mean 4.1 mmol/L, 95% CI 4.0, 4.2). In 24% of males and 48% of females, usual levels of physical activity were low, consistent with lower scores on fitness tests in females. Thirty percent of males and 24% of females regularly drank at "unsafe," levels while 26% of males and 29% of females smoked. Smoking was associated with "unsafe" drinking. Cardiovascular risk factors in 18-year-olds are related to smoking, "unsafe" drinking, and physical inactivity, particularly in females. These behaviors should be targeted in designing multimodal health promotion programs appropriate for these young adults.

Inhibition of 11-beta-hydroxysteroid dehydrogenase in pregnant rats and the programming of blood pressure in the offspring.

Recent epidemiological studies have linked low birth weight with the later occurrence of cardiovascular and metabolic disorders, particularly hypertension. We have proposed that fetal exposure to excess maternal glucocorticoids may underpin this association. Normally, the fetus is protected from maternal glucocorticoids by placental 11beta-hydroxysteroid dehydrogenase (11beta-HSD). We have previously shown that treatment of pregnant rats with dexamethasone, a synthetic glucocorticoid that is poorly metabolized by the enzyme, reduces birth weight and produces elevated blood pressure in the adult offspring. Moreover, low activity of placental 11beta-HSD correlates with low birth weight in rats. Here, we show that maternal administration of carbenoxolone, a potent inhibitor of 11 beta-HSD, throughout pregnancy leads to reduced birth weight (mean 20 percent decrease) and elevated blood pressures (increase in mean arterial pressure, 9 mm Hg in males, 7 mm Hg in females) in the adult offspring of carbenoxolone-treated rats. This effect requires the presence of maternal adrenal products, as carbenoxolone given to adrenalectomized pregnant rats had no effect on birth weight or blood pressure. These data support the hypothesis that excess exposure of the fetoplacental unit to maternal glucocorticoids reduces birth weight and programs subsequent hypertension and indicate a key role for placental 11beta-HSD in controlling such exposure.

A survey of blood pressure distribution in Pygmy and Bantu populations in Cameroon.

A blood pressure survey was performed in isolated Pygmy communities and Bantu population samples living either in close relationship with the Pygmies or in separate areas within the same region. The Pygmies are still living as hunter-gatherers, whereas the Bantus rely on agriculture for food provision. Mean blood pressures in Pygmies were 130/85 mm Hg in males and 126/80 mm Hg in females and in Bantus were 137/87 mm Hg in males and 136/84 mm Hg in females. In spot urine the mean urinary sodium concentration was higher in Bantus than Pygmies (86 versus 37 mmol/L in males; 95 versus 56 mmol/L in females). In the total population urinary potassium concentration was very high (150 mmol/L), calcium concentration very low (0.4 mmol/L), and urea concentration low (6.9 g/L). After adjustment for age, height, weight, and sex, no racial differences in blood pressure were present. Blood pressure increased with age but body mass index did not. Diastolic pressure correlated significantly but negatively with urinary sodium in multiple regression analysis. Our study demonstrates that blood pressure increases with age in hunter-gatherer populations on a low to moderately high sodium diet in the presence of a low urinary excretion of calcium coupled with a low protein intake.