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1.
Rev Med Suisse ; 19(841): 1642-1646, 2023 Sep 13.
Artigo em Francês | MEDLINE | ID: mdl-37702465

RESUMO

Detecting, treating and controlling hypertension remains a primary goal in health policy. New recommendations in the management of hypertension were published in 2023 to withhold its global pandemic. The first step is to initiate dual antihypertensive therapy in most of the cases by combining 2 molecules from different classes in a single tablet. Subsequent steps involve ensuring blood pressure control and, if indicated, combining other drug classes, again as a single pill combination (SPC). These polypills make it possible to reduce blood pressure more effectively, to offer earlier cardioprotection and to increase patient's compliance while simplifying their treatment and eliminating adverse effects. In this article, we will focus on the combination of antihypertensive classes as a revolutionary paradigm.


Dépister, traiter et contrôler l'HTA reste un objectif primordial de politique de santé. De nouvelles recommandations ont été publiées en 2023 afin d'endiguer cette pandémie mondiale. La première étape, pour la majorité des cas, consiste à instaurer une bithérapie en combinant 2 molécules de différentes classes en un seul comprimé (single pill combination (SPC)). Il faut ensuite s'assurer du bon contrôle tensionnel et, si indiqué, associer d'autres classes médicamenteuses, toujours sous forme de SPC. Ces polypill permettent d'être plus efficace pour réduire la TA, offrent une cardioprotection précoce et augmentent l'adhésion thérapeutique des patients tout en simplifiant leur traitement et en limitant les effets indésirables. Dans cet article, l'accent est mis sur l'association des classes d'antihypertenseurs, comme paradigme révolutionnaire.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Hipertensão , Humanos , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Pressão Sanguínea , Política de Saúde
2.
BMC Nephrol ; 22(1): 325, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592938

RESUMO

BACKGROUND: Hypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown. METHODS: We retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable. RESULTS: A total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m2 respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m2 higher eGFR. HT was negatively associated with eGFR (p = 0.003). CONCLUSIONS: We confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.


Assuntos
Pressão Sanguínea , Taxa de Filtração Glomerular , Hipertensão/fisiopatologia , Transplante de Rim , Rim/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
J Clin Endocrinol Metab ; 103(2): 748-758, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29077874

RESUMO

Context: Urinary cadmium (Cd) excretion is associated with cancer and cardiovascular morbidity. A potential mechanism could be disturbance of steroidogenesis in gonads and adrenal glands. Objective: We tested whether urinary excretion of Cd is correlated with that of cortico- and sex steroid metabolites in the general adult population. Setting: The Swiss Kidney Project on Genes in Hypertension is a multicentric, family-based population study. Measures: Urinary excretions of steroid hormone metabolites and Cd were measured with separate day and night collections. Associations were analyzed by mixed linear models. Results: Urinary Cd and testosterone excretions in men were significantly correlated (respective day and night ß values [standard error (SE)], 1.378 [0.242], P < 0.0005; and 1.440 [0.333], P < 0.0005), but not in women [0.333(0.257), P = 0.2; and 0.674 (0.361), P = 0.06]. Urinary Cd and cortisol excretions were positively associated in both sexes [day: ß = 0.475 (SE, 0.157), P = 0.0025, and 0.877 (SE, 0.194), P < 0.0005, respectively; night: ß = 0.875 (SE, 0.253), P < 0.0005 and 1.183 (SE, 0.277), P = 0.00002, respectively]. Cd excretion was correlated with mineralocorticoid metabolites excretion, except tetrahydroaldosterone, in both sexes (P < 0.01). There was an independent effect of Cd on sex hormone and corticosteroid synthesis and an interdependent effect on gluco- and mineralcorticoid production. Conclusion: Our findings provide evidence for a global stimulating effect on steroid synthesis already at low-dose Cd exposure. These findings might explain the association of Cd with diseases such as steroid-sensitive cancers or metabolic disorders.


Assuntos
Corticosteroides/metabolismo , Cádmio/urina , Hormônios Esteroides Gonadais/metabolismo , Hipertensão/metabolismo , Adulto , Idoso , Aldosterona/análogos & derivados , Aldosterona/urina , Estudos de Coortes , Família , Feminino , Hormônios Esteroides Gonadais/urina , Humanos , Hipertensão/urina , Rim/metabolismo , Masculino , Pessoa de Meia-Idade , Mineralocorticoides/urina , Testosterona/urina
4.
Ann Endocrinol (Paris) ; 77(3): 226-34, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27315759

RESUMO

Spironolactone, which is a potent mineralocorticoid receptor antagonist, represents the first line medical treatment of primary aldosteronism (PA). As spironolactone is also an antagonist of the androgen and progesterone receptor, it may present side effects, especially in male patients. In case of intolerance to spironolactone, amiloride may be used to control hypokaliemia and we suggest that eplerenone, which is a more selective but less powerful antagonist of the mineralocorticoid receptor, be used in case of intolerance to spironolactone and insufficient control of hypertension by amiloride. Specific calcic inhibitors and thiazide diuretics may be used as second or third line therapy. Medical treatment of bilateral forms of PA seem to be as efficient as surgical treatment of lateralized PA for the control of hypertension and the prevention of cardiovascular and renal morbidities. This allows to propose medical treatment of PA to patients with lateralized forms of PA who refuse surgery or to patients with PA who do not want to be explored by adrenal venous sampling to determine whether they have a bilateral or lateralized form.


Assuntos
Hiperaldosteronismo/tratamento farmacológico , Eplerenona , Feminino , França , Humanos , Hiperaldosteronismo/patologia , Hiperaldosteronismo/cirurgia , Hipertensão/tratamento farmacológico , Hipopotassemia/tratamento farmacológico , Masculino , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Espironolactona/efeitos adversos , Espironolactona/análogos & derivados , Espironolactona/uso terapêutico , Resultado do Tratamento
5.
Psychoneuroendocrinology ; 67: 76-85, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26881833

RESUMO

Allostatic load (AL) is a marker of physiological dysregulation which reflects exposure to chronic stress. High AL has been related to poorer health outcomes including mortality. We examine here the association of socioeconomic and lifestyle factors with AL. Additionally, we investigate the extent to which AL is genetically determined. We included 803 participants (52% women, mean age 48±16years) from a population and family-based Swiss study. We computed an AL index aggregating 14 markers from cardiovascular, metabolic, lipidic, oxidative, hypothalamus-pituitary-adrenal and inflammatory homeostatic axes. Education and occupational position were used as indicators of socioeconomic status. Marital status, stress, alcohol intake, smoking, dietary patterns and physical activity were considered as lifestyle factors. Heritability of AL was estimated by maximum likelihood. Women with a low occupational position had higher AL (low vs. high OR=3.99, 95%CI [1.22;13.05]), while the opposite was observed for men (middle vs. high OR=0.48, 95%CI [0.23;0.99]). Education tended to be inversely associated with AL in both sexes(low vs. high OR=3.54, 95%CI [1.69;7.4]/OR=1.59, 95%CI [0.88;2.90] in women/men). Heavy drinking men as well as women abstaining from alcohol had higher AL than moderate drinkers. Physical activity was protective against AL while high salt intake was related to increased AL risk. The heritability of AL was estimated to be 29.5% ±7.9%. Our results suggest that generalized physiological dysregulation, as measured by AL, is determined by both environmental and genetic factors. The genetic contribution to AL remains modest when compared to the environmental component, which explains approximately 70% of the phenotypic variance.


Assuntos
Alostase/genética , Alostase/fisiologia , Estilo de Vida , Classe Social , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Hypertension ; 66(1): 85-92, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25987667

RESUMO

Increased pulse wave velocity (PWV) is a marker of aortic stiffness and an independent predictor of mortality. Matrix Gla-protein (MGP) is a vascular calcification inhibitor that needs vitamin K to be activated. Inactive MGP, known as desphospho-uncarboxylated MGP (dp-ucMGP), can be measured in plasma and has been associated with various cardiovascular markers, cardiovascular outcomes, and mortality. In this study, we hypothesized that high levels of dp-ucMGP are associated with increased PWV. We recruited participants via a multicenter family-based cross-sectional study in Switzerland. Dp-ucMGP was quantified in plasma by sandwich ELISA. Aortic PWV was determined by applanation tonometry using carotid and femoral pulse waveforms. Multiple regression analysis was performed to estimate associations between PWV and dp-ucMGP adjusting for age, renal function, and other cardiovascular risk factors. We included 1001 participants in our analyses (475 men and 526 women). Mean values were 7.87±2.10 m/s for PWV and 0.43±0.20 nmol/L for dp-ucMGP. PWV was positively associated with dp-ucMGP both before and after adjustment for sex, age, body mass index, height, systolic and diastolic blood pressure (BP), heart rate, renal function, low- and high-density lipoprotein, glucose, smoking status, diabetes mellitus, BP and cholesterol lowering drugs, and history of cardiovascular disease (P≤0.01). In conclusion, high levels of dp-ucMGP are independently and positively associated with arterial stiffness after adjustment for common cardiovascular risk factors, renal function, and age. Experimental studies are needed to determine whether vitamin K supplementation slows arterial stiffening by increasing MGP carboxylation.


Assuntos
Proteínas de Ligação ao Cálcio/sangue , Proteínas da Matriz Extracelular/sangue , Rigidez Vascular/fisiologia , Adulto , Fatores Etários , Idoso , Glicemia/análise , Índice de Massa Corporal , Proteínas de Ligação ao Cálcio/química , Doenças Cardiovasculares/epidemiologia , Comorbidade , Estudos Transversais , Diabetes Mellitus/epidemiologia , Proteínas da Matriz Extracelular/química , Feminino , Hemodinâmica , Humanos , Rim/fisiologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fosforilação , Processamento de Proteína Pós-Traducional , Análise de Onda de Pulso , Estudos de Amostragem , Fumar/epidemiologia , Suíça/epidemiologia , Proteína de Matriz Gla
7.
BMC Med ; 13: 40, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25858764

RESUMO

BACKGROUND: Urinary creatinine excretion is used as a marker of completeness of timed urine collections, which are a keystone of several metabolic evaluations in clinical investigations and epidemiological surveys. METHODS: We used data from two independent Swiss cross-sectional population-based studies with standardised 24-hour urinary collection and measured anthropometric variables. Only data from adults of European descent, with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2 and reported completeness of the urinary collection were retained. A linear regression model was developed to predict centiles of the 24-hour urinary creatinine excretion in 1,137 participants from the Swiss Survey on Salt and validated in 994 participants from the Swiss Kidney Project on Genes in Hypertension. RESULTS: The mean urinary creatinine excretion was 193 ± 41 µmol/kg/24 hours in men and 151 ± 38 µmol/kg/24 hours in women in the Swiss Survey on Salt. The values were inversely correlated with age and body mass index (BMI). CONCLUSIONS: We propose a validated prediction equation for 24-hour urinary creatinine excretion in the general European population, based on readily available variables such as age, sex and BMI, and a few derived normograms to ease its clinical application. This should help healthcare providers to interpret the completeness of a 24-hour urine collection in daily clinical practice and in epidemiological population studies.


Assuntos
Biomarcadores/urina , Creatinina/urina , Urinálise/normas , Adulto , Idoso , Antropometria , Índice de Massa Corporal , Estudos Transversais , Etnicidade , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Valores de Referência , Suíça
8.
J Am Soc Nephrol ; 26(6): 1415-25, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25270071

RESUMO

Arginine vasopressin (AVP) has a key role in osmoregulation by facilitating water transport in the collecting duct. Recent evidence suggests that AVP may have additional effects on renal function and favor cyst growth in polycystic kidney disease. Whether AVP also affects kidney structure in the general population is unknown. We analyzed the association of copeptin, an established surrogate for AVP, with parameters of renal function and morphology in a multicentric population-based cohort. Participants from families of European ancestry were randomly selected in three Swiss cities. We used linear multilevel regression analysis to explore the association of copeptin with renal function parameters as well as kidney length and the presence of simple renal cysts assessed by ultrasound examination. Copeptin levels were log-transformed. The 529 women and 481 men had median copeptin levels of 3.0 and 5.2 pmol/L, respectively (P<0.001). In multivariable analyses, the copeptin level was associated inversely with eGFR (ß=-2.1; 95% confidence interval [95% CI], -3.3 to -0.8; P=0.002) and kidney length (ß=-1.2; 95% CI, -1.9 to -0.4; P=0.003) but positively with 24-hour urinary albumin excretion (ß=0.11; 95% CI, 0.01 to 0.20; P=0.03) and urine osmolality (ß=0.08; 95% CI, 0.05 to 0.10; P<0.001). A positive association was found between the copeptin level and the presence of renal cysts (odds ratio, 1.6; 95% CI, 1.1 to 2.4; P=0.02). These results suggest that AVP has a pleiotropic role in renal function and may favor the development of simple renal cysts.


Assuntos
Arginina Vasopressina/metabolismo , Glicopeptídeos/metabolismo , Doenças Renais Policísticas/metabolismo , Doenças Renais Policísticas/fisiopatologia , Adulto , Análise de Variância , Biomarcadores/metabolismo , Intervalos de Confiança , Estudos Transversais , Feminino , Seguimentos , Taxa de Filtração Glomerular/fisiologia , Humanos , Rim/fisiopatologia , Testes de Função Renal , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Valores de Referência , Estudos Retrospectivos , Índice de Gravidade de Doença , Suíça , Urinálise
9.
Rev Med Suisse ; 10(441): 1650-2, 1654-5, 2014 Sep 10.
Artigo em Francês | MEDLINE | ID: mdl-25322623

RESUMO

Pheochromocytomas (PHEO) and paragangliomas (PGL) are rare neuroendocrine tumors secreting catecholamines in most cases. The clinic can be very variable. Morbidity and mortality PHEO and PGL are primarily cardiovascular and haves catecholamine-mediated origin. The PHEO and PGL can sign in with a syndromic association with multiple tumors and genetic counseling is necessary in search of a germline mutation. The first step includes a diagnostic assay of metanephrine and normetanephrines. In case of positive biology a CT or MRI imaging will be needed to locate the tumor. Treatment with alpha-blocker before surgery reduces the perioperative risk. A long term follow up is recommended to detect recurrence.


Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Paraganglioma/diagnóstico , Feocromocitoma/diagnóstico , Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias das Glândulas Suprarrenais/terapia , Clínicos Gerais , Humanos , Masculino , Pessoa de Meia-Idade , Paraganglioma/patologia , Paraganglioma/terapia , Feocromocitoma/patologia , Feocromocitoma/terapia
10.
Hypertension ; 63(1): 136-42, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24126174

RESUMO

Increased renal resistive index (RRI) has been recently associated with target organ damage and cardiovascular or renal outcomes in patients with hypertension and diabetes mellitus. However, reference values in the general population and information on familial aggregation are largely lacking. We determined the distribution of RRI, associated factors, and heritability in a population-based study. Families of European ancestry were randomly selected in 3 Swiss cities. Anthropometric parameters and cardiovascular risk factors were assessed. A renal Doppler ultrasound was performed, and RRI was measured in 3 segmental arteries of both kidneys. We used multilevel linear regression analysis to explore the factors associated with RRI, adjusting for center and family relationships. Sex-specific reference values for RRI were generated according to age. Heritability was estimated by variance components using the ASSOC program (SAGE software). Four hundred women (mean age±SD, 44.9±16.7 years) and 326 men (42.1±16.8 years) with normal renal ultrasound had mean RRI of 0.64±0.05 and 0.62±0.05, respectively (P<0.001). In multivariable analyses, RRI was positively associated with female sex, age, systolic blood pressure, and body mass index. We observed an inverse correlation with diastolic blood pressure and heart rate. Age had a nonlinear association with RRI. We found no independent association of RRI with diabetes mellitus, hypertension treatment, smoking, cholesterol levels, or estimated glomerular filtration rate. The adjusted heritability estimate was 42±8% (P<0.001). In a population-based sample with normal renal ultrasound, RRI normal values depend on sex, age, blood pressure, heart rate, and body mass index. The significant heritability of RRI suggests that genes influence this phenotype.


Assuntos
Pressão Sanguínea/fisiologia , Hipertensão/fisiopatologia , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Ultrassonografia Doppler Dupla , Resistência Vascular/fisiologia , Adulto , Fatores Etários , Pressão Sanguínea/genética , Estudos Transversais , Família , Feminino , Humanos , Rim/fisiologia , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais , Suíça , Resistência Vascular/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-23579266

RESUMO

The impact of impaired circadian rhythm on health has been widely studied in shift workers and trans-meridian travelers. A part from its correlation with sleep and mood disorders, biological rhythm impairment is a recognized risk factor for cardiovascular diseases and breast cancer. Preeclampsia is a major public health issue, associated with a significant maternal and fetal morbidity and mortality worldwide. While the risks factors for this condition such as obesity, diabetes, pre-existing hypertension have been identified, the underlying mechanism of this multi-factorial disease is yet not fully understood. The disruption of the light/dark cycle in pregnancy has been associated with adverse outcomes. Slightly increased risk for "small for gestational age" babies, "low birth weight" babies, and preterm deliveries has been reported in shift working women. Whether altered circadian cycle represents a risk factor for preeclampsia or preeclampsia is itself linked with an abnormal circadian cycle is less clear. There are only few reports available, showing conflicting results. In this review, we will discuss recent observations concerning circadian pattern of blood pressure in normotensive and hypertensive pregnancies. We explore the hypothesis that circadian misalignments may represent a risk factor for preeclampsia. Unraveling potential link between circadian clock gene and preeclampsia could offer a novel approach to our understanding of this multi-system disease specific to pregnancy.

12.
PLoS One ; 7(6): e39877, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22761919

RESUMO

BACKGROUND: There are no time trends in prevalence, unawareness, treatment, and control of hypertension in Switzerland. The objective of this study was to analyze these trends and to determine the associated factors. METHODS/FINDINGS: Population-based study conducted in the Canton of Geneva, Switzerland, between 1999 and 2009. Blood pressure was measured thrice using a standard protocol. Hypertension was defined as mean systolic or diastolic blood pressure ≥ 140/90 mmHg or self-reported hypertension or anti-hypertensive medication. Unawareness, untreated and uncontrolled hypertension was determined by questionnaires/blood pressure measurements. Yearly age-standardized prevalences and adjusted associations for the 1999-2003 and 2004-2009 survey periods were reported. The 10-year survey included 9,215 participants aged 35 to 74 years. Hypertension remained stable (34.4%). Hypertension unawareness decreased from 35.9% to 17.7% (P<0.001). The decrease in hypertension unawareness was not paralleled by a concomitant absolute increase in hypertension treatment, which remained low (38.2%). A larger proportion of all hypertensive participants were aware but not treated in 2004-2009 (43.7%) compared to 1999-2003 (33.1%). Uncontrolled hypertension improved from 62.2% to 40.6% between 1999 and 2009 (P = 0.02). In 1999-2003 period, factors associated with hypertension unawareness were current smoking (OR = 1.27, 95%CI, 1.02-1.59), male gender (OR = 1.56, 1.27-1.92), hypercholesterolemia (OR = 1.31, 1.20-1.44), and older age (OR 65-74 yrs vs 35-49 yrs = 1.56, 1.21-2.02). In 1999-2003 and 2004-2009, obesity and diabetes were negatively associated with hypertension unawareness, high education was associated with untreated hypertension (OR = 1.45, 1.12-1.88 and 1.42, 1.02-1.99, respectively), and male gender with uncontrolled hypertension (OR = 1.49, 1.03-2.17 and 1.65, 1.08-2.50, respectively). Sedentarity was associated with higher risk of hypertension and uncontrolled hypertension in 1999-2003. CONCLUSIONS: Hypertension prevalence remained stable since 1999 in the canton of Geneva. Although hypertension unawareness substantially decreased, more than half of hypertensive subjects still remained untreated or uncontrolled in 2004-2009. This study identified determinants that should guide interventions aimed at improving hypertension treatment and control.


Assuntos
Conscientização , Hipertensão/epidemiologia , Adulto , Idoso , Humanos , Hipertensão/prevenção & controle , Hipertensão/terapia , Renda , Pessoa de Meia-Idade , Prevalência , Suíça/epidemiologia
13.
Curr Opin Nephrol Hypertens ; 16(1): 16-21, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17143066

RESUMO

PURPOSE OF REVIEW: The aim of this article is to discuss the impact of male and female sex hormones on renal function and to develop the concept that salt-sensitivity of renal function behaves independently of the systemic blood pressure response to salt and may contribute to renal sex-specific differences. RECENT FINDINGS: Men exhibit a more rapid age-related decline in renal function than women and some renal diseases are clearly sex dependent. Recent studies have shown that gonadal steroids have an important influence on sodium handling and renal hemodynamics that may offer a key for understanding the sexual dimorphism of the renal function. It has been found that androgens increase proximal sodium reabsorption and intraglomerular pressure by modulating afferent and efferent arteriolar tonus via angiotensin II, endothelin and oxidative stress. In contrast, female sex hormones lead to a renal vasodilation and decrease filtration fraction. SUMMARY: Some newly discovered mechanisms triggering the salt-sensitivity of the renal function and the interaction between gonadal steroids and components of the renin cascade may play an important role in the dimorphism of renal response to salt.


Assuntos
Hormônios Esteroides Gonadais/fisiologia , Rim/fisiologia , Sódio/metabolismo , Androgênios/fisiologia , Estrogênios/fisiologia , Feminino , Humanos , Rim/metabolismo , Masculino , Progesterona/fisiologia , Sistema Renina-Angiotensina/fisiologia , Caracteres Sexuais
14.
Kidney Int ; 64(4): 1374-80, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12969156

RESUMO

BACKGROUND: The use of oral contraceptives is associated with an increased risk of developing hypertension but the mechanisms of this hypertensive effect are not completely defined. The purpose of the present study was to assess prospectively the systemic and renal hemodynamic and tubular responses to salt in women taking oral contraceptives. METHODS: Twenty seven young healthy normotensive women taking oral contraceptives containing monophasic combination of 30 microg ethynilestradiol and 150 microg desogestrel for>6 months were enrolled. All women were assigned at random to receive a low (40 mmol/day) or a high (250 mmol/day) sodium diet for 1 week on two consecutive menstrual cycles during the active oral contraceptive phase. At the end of each diet period, 24-hour ambulatory blood pressure, renal hemodynamics, sodium handling, and hormonal profile were measured. RESULTS: The blood pressure response to salt on oral contraceptives was characterized by a salt-resistant pattern with a normal circadian rhythm. Salt loading results in an increase in glomerular filtration rate (GFR) (P < 0.05 vs. low salt), with no change in the renal plasma flow, thus leading to an increase in the filtration fraction (P < 0.05). At the tubular level, women on oral contraceptives responded to a low salt intake with a marked increased in proximal sodium conservation (P < 0.01 vs. high salt) and with an almost complete reabsorption of sodium reaching the distal tubule. After sodium loading, both the proximal and the distal reabsorption of sodium decreased significantly (P < 0.01). CONCLUSION: The use of oral contraceptives is not associated with an increased blood pressure response to salt in young normotensive women. However, oral contraceptives affect the renal hemodynamic response to salt, a high salt intake leading to an increase in GFR and filtration fraction. This effect is possibly mediated by the estrogen-induced activation of the renin-angiotensin system. Oral contraceptives also appear to increase the tubular responsiveness to changes in sodium intake. Taken together, these data point out evidence that synthetic sex steroids have a significant impact on renal function in women. The renal effects of oral contraceptives should be taken into account when managing young women with renal diseases.


Assuntos
Anticoncepcionais Orais/farmacologia , Túbulos Renais/efeitos dos fármacos , Circulação Renal/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Hormônios/sangue , Humanos , Rim/metabolismo , Sódio/metabolismo
15.
Kidney Int ; 61(2): 425-31, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11849382

RESUMO

BACKGROUND: It has been suggested that women gain weight and develop peripheral edema during the luteal phase of the menstrual cycle because they tend to retain sodium and water. However, there is actually no clear evidence for physiological, cyclic variations in renal sodium handling during the menstrual cycle. We prospectively assessed the changes in segmental renal sodium handling occurring during the menstrual cycle in response to changes in salt intake. METHODS: Thirty-five normotensive women were enrolled. Seventeen women were randomized and studied in the follicular and 18 in the luteal phases of their menstrual cycle. All women were assigned at random to receive a low (40 mmol/day) or a high (250 mmol/day) sodium diet for seven days on two consecutive menstrual cycles. Renal sodium handling and hemodynamics were measured at the end of each diet period. RESULTS: The changes in sodium intake induced comparable variations in sodium excretion in both phases of the menstrual cycle. In the follicular phase, the increase in salt intake was associated with no change in renal hemodynamics, an increased fractional excretion of lithium (FELi) and a decreased fractional distal reabsorption of sodium (FDRNa), suggesting that sodium reabsorption is reduced both in the proximal and the distal tubules. In contrast, in the luteal phase, the renal response to salt was characterized by a significant renal vasodilation and a marked salt escape from the distal nephron, compared to the women investigated in the follicular phase (P < 0.01). Sodium reabsorption by the proximal nephron was not reduced as indicated by the unchanged FELi. CONCLUSIONS: These results show that the segmental renal handling of sodium differs markedly in the two phases of the menstrual cycle. They suggest that the female hormones modulate the renal handling of sodium at the proximal and distal segments of the nephron in young normotensive women.


Assuntos
Fase Folicular/metabolismo , Túbulos Renais Distais/metabolismo , Túbulos Renais Proximais/metabolismo , Fase Luteal/metabolismo , Cloreto de Sódio na Dieta/farmacocinética , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Pressão Sanguínea/efeitos dos fármacos , Feminino , Humanos , Lítio/metabolismo , Progesterona/sangue , Estudos Prospectivos , Circulação Renal/efeitos dos fármacos , Renina/sangue , Equilíbrio Hidroeletrolítico/fisiologia
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