Jp Degaute

Circadian rhythms of blood pressure after liver transplantation

Twenty-four-hour systolic blood pressure, diastolic blood pressure, and heart rate profiles were recorded in 17 liver-transplanted patients by noninvasive ambulatory monitoring and were analyzed with the periodogram method. These recordings were compared with those of control subjects matched for age, sex, and daytime ambulatory blood pressure. Abnormal blood pressure patterns were found in seven of the 17 patients, whereas the other 10 patients had circadian blood pressure profiles that were not different from those of control subjects. These two groups of liver-transplanted patients did not differ in age, sex, oral dose of cyclosporine, specific serum cyclosporine level, and proportion of patients receiving azathioprine and antihypertensive medications. In contrast, the daily oral dose of prednisolone was significantly higher (p < 0.001) in the seven patients with abnormal circadian blood pressure patterns. Moreover, only the daily oral dose of prednisolone was inversely correlated with the magnitude of the nighttime systolic and diastolic blood pressure decrease (r = -0.64 and r = -0.66, p < 0.01). In contrast to blood pressure, patients and control subjects had similar circadian heart rate variations. We conclude that exogenous glucocorticoid administration may have a dose-dependent effect on the nighttime blood pressure fall and may play an important role in the pathogenesis of the abnormal circadian blood pressure profiles observed in liver-transplanted patients.

Sympathetic Rhythmicity in Cardiac Transplant Recipients

BACKGROUND Variability of R-R interval and muscle sympathetic nerve activity (MSNA) occurs predominantly at a low frequency (LF, +/-0.1 Hz) and a high frequency (HF, +/-0.25 Hz) in normal humans. Increased sympathetic drive in normal humans is associated with an increased LF component of the R-R interval and MSNA. Patients with severe heart failure have high sympathetic activity but decreased or absent LF power of both R-R and MSNA. We tested the hypothesis that this dysfunction in autonomic modulation in heart failure can be reversed by heart transplantation. METHODS AND RESULTS We performed spectral analysis of resting MSNA, R-R interval, and respiration in 9 patients with heart transplants, 9 chronic heart failure patients, and 9 normal control subjects, all closely matched for age, sex, and body mass index. MSNA (bursts per minute) was higher in patients with heart transplants (74+/-3) than either patients with heart failure (56+/-6) or normal subjects (40+/-4) (P<0.001). LF variability in the R-R interval was reduced in both heart transplant recipients and heart failure patients compared with the control subjects (P<0.01). The LF variability in MSNA was also nearly absent in the heart failure patients (P<0.01). However, the LF and HF oscillations in MSNA in patients with heart transplants were comparable to those evident in the control subjects. CONCLUSIONS Cardiac transplantation does not reduce MSNA. However, LF oscillations in sympathetic activity are restored after transplantation such that the MSNA oscillatory profile is similar to that observed in normal subjects.

Does cardiac denervation affect the short-term blood pressure variability in humans?

Objective To explore the repercussion of cardiac denervation on the short-term blood pressure variability in humans, in order to assess the extent to which the variability of blood pressure is linked to the variability of heart rate. Methods Beat-to-beat blood pressure and RR interval time were recorded in 16 heart-transplanted patients and were compared with those of 10 healthy control subjects in the resting supine, sitting and standing positions. Blood pressure and RR interval variabilities were assessed by spectral analysis. Results The total blood pressure power and the supine and sitting very low-frequency, low-frequency and high-frequency blood pressure variability were similar in the heart-transplanted patients and in the controls, despite a marked reduction in the RR interval variability in the heart-transplanted patients. However, the heart-transplanted patients had lower standing low-frequency blood pressure variability than the control subjects. Moreover, very low-frequency and low-frequency RR interval variabilities reappeared in the long-term heart-transplanted patients but not in the short-term heart-transplanted patients (range of time after transplantation 53–124 and 3–25 months, respectively). Conclusions Short-term RR interval fluctuations are not mandatory for the maintenance of normal blood pressure variability in the supine and sitting positions, but may contribute to the increase in the low-frequency blood pressure variability which occurs normally in the standing position. Moreover, the long-term heart-transplanted patients had increased RR interval variability, which may have been caused by the reappearance of limited autonomic cardiac modulation. However, this increased RR interval variability did not affect the corresponding blood pressure variability.

[PP.16.11] HYPERTENSION IN CAMEROONIAN RURAL AND URBAN PYGMIES AND BANTUS OF SOUTHERN REGION

Objective: To determine the prevalence of hypertension and its correlates among pygmy and Bantu dwellers in rural and urban environments of southern Cameroon Design and method: In this cross-sectional cluster sampling survey, we compared 100 traditional pygmies (TP) living in forest (Lolodorf) under hunter-gatherer subsistence mode and 100 traditional Bantus (TB) living in Bidjouka village closed to Lolodorf, to 100 contemporary pygmies (CP) and 100 contemporary Bantus (CB) both living in the same urban environment in Kribi. Trained observers recorded in each participant lifestyle and socio-demographic data, height, weight, body mass index (BMI), waist circumference and blood pressure (BP). Brachial systolic BP (SBP) and diastolic BP (DBP) were measured in triplicate using an automatic sphygmomanometer (Omron 705 CP). Hypertension was considered for SBP/DBP> or = 140/90 mmHg. Results: Pygmies were younger than Bantus: mean age = 38 ± 16 vs 45 ± 17 years, p = 0.0001. Overweight/obesity (23.5% vs 42%), abdominal obesity (1% vs 16%) and alcohol consumption (48% vs 59.5%) rates were lower in pygmies than in Bantus (all p < 0.01). By contrast, smoking rate was greater in pygmies than in Bantus (47.5% vs 35%, p = 0.015). Age-adjusted prevalence of hypertension was lower in pygmies than Bantus globally (7.5% vs 21.5% p = 0.0001), and in rural and urban settings: 4% vs 19% and 11% vs 24 %, respectively, both p < 0.01). In pygmies taken separately, the age-adjusted prevalence of hypertension was lower in TP than in CP (4% vs 11%). Multivariate logistic regression analysis performed in the whole study population revealed that hypertension was independently associated with urban environment (OR = 2.15, 95%CI: 1.14–4.05), Bantu status (OR = 2.17, 95%CI: 1.09–4.34), age > or = 50 years (OR = 2.15, 95%CI: 1.14–4.05), and abdominal obesity (OR = 0.20 95%CI: 0.09–0.46) (all p < 0.05). In pygmies taken separately, age > or = 50 years (OR = 3.83, CI95%: 1.33–11.36) and urban environment (OR = 3.33, CI95%: 1.04–11.11) (both p < 0.05) emerged as independent determinants of hypertension. Conclusions: This study demonstrates that hunter-gatherer subsistence mode is associated with lower prevalence of hypertension as observed in TP. Hypertension is more common in Bantus and CP, and driven mostly by their westernized lifestyle and the growing urbanization of rural area.

[PP.30.10] INFLUENCE OF URINARY SODIUM AND POTASSIUM EXCRETION ON BLOOD PRESSURE IN CAMEROONIAN PYGMIES AND BANTUS

Objective: High dietary salt increases blood pressure (BP) and is a leading cause of hypertension. This study aimed to examine association between urinary sodium and potassium excretion with BP among Cameroonian pygmies under hunter-gatherer subsistence mode and Bantus, living in urban area under westernized lifestyle. Design and method: We randomly enrolled 150 Pygmies living in the Lolodorf municipality (rural area) and 150 Bantus living in Douala (urban area). Height, weight, body mass index (BMI), waist circumference (WC), BP and single overnight spot urine samples were obtained. Brachial systolic BP (SBP) and diastolic BP (DBP) were measured in triplicate using an automatic device (Omron 705 CP). Urinary sodium and potassium concentration was determined by flame photometry and was used as surrogates for salt intake. Results: As Compared to Bantus, Pygmies were shorter with a lower body weight (all P < 0001) and had a lower age-standardized prevalence of hypertension (3.3 % vs 28 %) (all P < 0.0001). Age-adjusted SBP and DBP were lower in Pygmies than in Bantus (all P < 0.001). Both SBP and DBP increased with age but to a lesser extent in Pygmies (both P < 0.01). Urinary sodium excretion was lower in Pygmies than in Bantus (46.9 ± 32.4 vs 121.5 ± 61.0 mmol/L, P < 0.0001). Age-adjusted SBP and DBP were positively associated with urinary sodium concentration in Bantus (all p < 0.05), but not in Pygmies. In the two groups, urinary potassium concentration was similar, and was not related to BP (all >0.05). In the whole study population and in Bantus taken separately, urinary sodium excretion was higher in hypertensive than in normotensive subjects (P < 0.0001). Multivariate logistic regression analysis showed that urinary sodium excretion, Bantu status and age are independent determinants of hypertension in the whole study population (P < 0.0001). Conclusions: The present study demonstrates that hunter-gatherer living is associated with low level of urinary sodium concentration which likely explains the low rates of hypertension and slower increase of BP with age in traditional pygmies. Hypertension is more common and urinary sodium concentration is higher in Bantus. Urinary salt excretion emerged as an independent predictor of hypertension in this Cameroonian population.

EFFECTS OF HUNTER-GATHER SUBSISTENCE MODE ON ARTERIAL DISTENSIBILITY: 3C.04

Objective: to assess whether arterial distensibility estimated by pulse wave velocity (PWV) and aortic augmentation index (AI) differs between Cameroon forest Pygmies (PF) on hunter-gather subsistence mode, Pygmies who migrated to semi-urban area (PM) and the Bantu farmers (BF) sharing the same environment. Methods: We recorded carotid-femoral PWV in age and gender carefully matched 20 PF, 22 BF and 12 PM. Aortic AI and pressures were generated from pressure wave analysis. Pulse pressure was systolic minus diastolic pressure; mean arterial pressure was diastolic plus one-third of pulse pressure. Cholesterol profile was determined in all participants. Results: PF were shorter than BF and PM (P = 0.02) with lower BMI in comparison to BF and PM (P < 0.01). PF had lower LDL-Cholesterol but higher HDL-cholesterol than BF (P < 0.01). Their PWV (5.81 ± 0.21 m/s) was lower (P = 0.01) in comparison to PM (6.72 ± 0.35 m/s) or BF (6.93 ± 0.29 m/s), even after adjustment for MAP (P = 0.002). By contrast, PWV adjusted for BMI did not differ between groups (P = 0.30). In the whole study population but not in PF taken separately, PWV increased (P < 0.05) with age, MAP, and BMI. Being PF was associated with lower PWV. Multivariate analysis revealed that PWV was independently associated with PF status and age (P < 0.001).). Neither LDL-cholesterol, nor HDL-cholesterol was related to PWV. No difference in AI corrected for heart rate (AIx) was observed between groups. In univariate analysis, AIx was positively associated with age, and MAP, and negatively with height and weight (all P < 0.05). Using stepwise multiple regression analysis age and height emerged as independent determinants of Aix (R2 = 0.52; P < 0.001). Conclusions: Hunter-gather subsistence mode is associated with low atherosclerosis risk translated by lower aortic stiffness attributed at least partly to low BMI and blunted effects of aging and BP on PF arterial structure and function. The similarity of AIx in the tree groups could be accounted for by early wave reflections in relation to PF shorter stature.

GENDER DIFFERENCE IN THE BURDEN OF CARDIOVASCULAR RISK FACTORS AMONG RURAL AND URBAN ADULT CAMEROONIAN POPULATIONS. RESULTS FROM THE VITARAA STUDY: PP.7.284

Objective: We investigated the profile of cardiovascular risk among adult in rural and urban Cameroon and assessed gender influence. Methods: Trained health professionals obtained anthropometric data, lifestyle habits, history and use of medication for chronic diseases in a random sample of urban and rural 2180 Cameroonians ≥20 years (1095 women). They measured sitting blood pressure twice using an electronic device. They determined casual plasma glucose and lipid concentrations. Results: The prevalence of cv risk factors was 20.6% for obesity (women 28.5 % vs men 12.6%;P < 0.001) central obesity 33.4% (55.5% vs 11.8%; P < 0.0001), diabetes 5.4% (6.1% vs 4.8%; P > 0.05), hypertension 31.7% (36.1% vs 27.3%; P < 0.001), smoking 10.4% (2.6%vs 18.1%; P < 0.001), alcohol intake 84.5% (81.5% vs 87.4%; P < 0.001), physical activity 18.8% (8.9% vs 28.7%; P < 0.001) and hypercholesterolemia 20.1% (27.1% vs 11.2%; P < 0.001). Consumption of vegetables was similar, that of fruits was less (P < 0.05) in women. The gender pattern was similar in rural and urban settings. However, rural women had lower rates of obesity (23.1% vs 32.1%; P = 0.003), hypertension (32.2% vs 38.6%; P = 0.031), diabetes (4.0% vs 7.4%; P = 0.015), smoking (2.4% vs 2.7%; P = 0.74) and hypercholesterolemia (14.8% vs 31.3%; P = 0.003) than urban women whereas their rates of physical activity (10.0% vs 8.2%; P = 0.30), legumes (43.8% vs 28%; P < 0.001) and fruits (28.2% vs 23.4%; P = 0.080) consumption tended to be higher. Rural men showed lower prevalence of obesity (9.4% vs 15.25; P = 0.003), hypertension (18.5% vs 33.8%; P < 0.001), smoking (12.9% vs 16.2%; P = 0.05) and hypercholesterolemia (6.2% vs 14.5%; P = 0.045) but rates of increased legumes (42.8% vs 26.2%; P < 0.001) and fruits (28.2% vs 21.6%; P < 0.001) consumption. Conclusion: The data highlght elevated prevalence of cardiovascular risk factors in rural and urban Cameroonians especially in women, and stress the need to implement appropriate cost effective peventive and control strategies.

PARADOXAL EFFECT OF LEGUMES CONSUMPTION ON CARDIOVASCULAR RISK FACTORS IN ADULT INHABITANTS OF CENTRAL AFRICA: RESULTS OF THE VITARAA STUDY: PP.7.294

Objective: To evaluate the relation between usual consumption of legumes and fruits and the prevalence of cardiovascular risk factors in the Africans. Methods: We collected anthropometric data, life habits, medical history and weekly consumption of fruits and legumes in 4196 subjects (≥20years; 2282 women) from randomly selected rural and urban Congolese and Cameroonians households. We recorded two blood pressure measurements that were averaged and obtained casual glycaemia and cholesterol concentration. Hypertension and diabetes were self reported diagnoses or, respectively, blood pressure≥140/90mmHg or glycaemia≥200 mg/dL. Results: Rural Africans had lower prevalence of hypertension (28.2% vs 34.8%), diabetes (3.4%vs5.6%), obesity (13.3vs18.9%), abdominal obesity (27.1%vs32.1%) and hypercholesterolemia (10.1%vs28.7%) than urban dwellers. In both areas, obesity and hypercholesterolemia predominated (P < 0.01) among women. High and low legumes consumers had respective prevalence of.35.8%vs 28.0% (P < 0.001) for hypertension, 6.7% vs 3.8% (P = 0.037) for diabetes, 29.5%vs29.0 (P = 0,75) for abdominal obesity, and 30.2%vs22.4% (P = 0.005) for hypercholesterolemia. High and low fruits consumers had respective prevalence of 28.7%vs34.2% (P = 0.0011) for hypertension, 4.7%vs5.6% (P = 0.22) for diabetes, 27.7%vs31.7% (P = 0.0164) for abdominal obesity, and 20.4% vs 27.6% (P = 0.0120) for hypercholesterolemia. These trends were similar in rural and urban areas taken separately. In multivariable-adjusted analysis, the probability of hypertension (OR:1.59;P < 0.001) or diabetes (OR:1.55;P = 0.0305) increased with higher legumes consumption and decreased with higher fruits intake (OR for hypertension:0.80;P = 0.0295). Conclusion: Whilst our rural-urban pattern of risk factors and the protective effect of fruits are expected findings, way legumes are processed in our region could be the culprit behind their paradoxical offending effect.