Detection of renal dysfunction based on serum creatinine levels in a Brazilian community: the Bambuí Health and Ageing Study

There are few population-based studies of renal dysfunction and none conducted in developing countries. In the present study the prevalence and predictors of elevated serum creatinine levels (SCr > or = 1.3 mg/dl for men and 1.1 mg/dl for women) were determined among Brazilian adults (18-59 years) and older adults (>60 years). Participants included all older adults (N = 1742) and a probabilistic sample of adults (N = 818) from Bambuí town, MG, Southeast Brazil. Predictors were investigated using multiple logistic regression. Mean SCr levels were 0.77 ± 0.15 mg/dl for adults, 1.02 ± 0.39 mg/dl for older men, and 0.81 ± 0.17 mg/dl for older women. Because there were only 4 cases (0.48%) with elevated SCr levels among adults, the analysis of elevated SCr levels was restricted to older adults. The overall prevalence of elevated SCr levels among the elderly was 5.09% (76/1494). The prevalence of hypercreatinemia increased significantly with age (chi² = 26.17, P = 0.000), being higher for older men (8.19%) than for older women (5.29%, chi² = 5.00, P = 0.02). Elevated SCr levels were associated with age 70-79 years (odds ratio [OR] = 2.25, 95% confidence interval [CI]: 1.15-4.42), hypertension (OR = 3.04, 95% CI: 1.34-6.92), use of antihypertensive drugs (OR = 2.46, 95% CI: 1.26-4.82), chest pain (OR = 3.37, 95% CI: 1.31-8.74), and claudication (OR = 3.43, 95% CI: 1.30-9.09) among men, and with age >80 years (OR = 4.88, 95% CI: 2.24-10.65), use of antihypertensive drugs (OR = 4.06, 95% CI: 1.67-9.86), physical inactivity (OR = 2.11, 95% CI: 1.11-4.02) and myocardial infarction (OR = 3.89, 95% CI: 1.58-9.62) among women. The prevalence of renal dysfunction observed was much lower than that reported in other population-based studies, but predictors were similar. New investigations are needed to confirm the variability in prevalence and associated factors of renal dysfunction among populations.

Age effects on the pharmacokinetics of tityustoxin from Tityus serrulatus scorpion venom in rats

The pharmacokinetics of scorpion venom and its toxins has been investigated in experimental models using adult animals, although, severe scorpion accidents are associated more frequently with children. We compared the effect of age on the pharmacokinetics of tityustoxin, one of the most active principles of Tityus serrulatus venom, in young male/female rats (21-22 days old, N = 5-8) and in adult male rats (150-160 days old, N = 5-8). Tityustoxin (6 µg) labeled with 99mTechnetium was administered subcutaneously to young and adult rats. The plasma concentration vs time data were subjected to non-compartmental pharmacokinetic analysis to obtain estimates of various pharmacokinetic parameters such as total body clearance (CL/F), distribution volume (Vd/F), area under the curve (AUC), and mean residence time. The data were analyzed with and without considering body weight. The data without correction for body weight showed a higher Cmax (62.30 ± 7.07 vs 12.71 ± 2.11 ng/ml, P < 0.05) and AUC (296.49 ± 21.09 vs 55.96 ± 5.41 ng h-1 ml-1, P < 0.05) and lower Tmax (0.64 ± 0.19 vs 2.44 ± 0.49 h, P < 0.05) in young rats. Furthermore, Vd/F (0.15 vs 0.42 l/kg) and CL/F (0.02 ± 0.001 vs 0.11 ± 0.01 l h-1 kg-1, P < 0.05) were lower in young rats. However, when the data were reanalyzed taking body weight into consideration, the Cmax (40.43 ± 3.25 vs 78.21 ± 11.23 ng kg-1 ml-1, P < 0.05) and AUC (182.27 ± 11.74 vs 344.62 ± 32.11 ng h-1 ml-1, P < 0.05) were lower in young rats. The clearance (0.03 ± 0.002 vs 0.02 ± 0.002 l h-1 kg-1, P < 0.05) and Vd/F (0.210 vs 0.067 l/kg) were higher in young rats. The raw data (not adjusted for body weight) strongly suggest that age plays a pivotal role in the disposition of tityustoxin. Furthermore, our results also indicate that the differences in the severity of symptoms observed in children and adults after scorpion envenomation can be explained in part by differences in the pharmacokinetics of the toxin.

Prevalence of low trauma fractures in long-term kidney transplant patients with preserved renal function

We evaluated the prevalence of low bone mineral density (BMD) and osteoporotic fractures in kidney transplantation (KT) patients and determined risk factors associated with osteoporotic fractures. The study was conducted on 191 patients (94 men and 97 women) with first KT for 3 years or more presenting stable and preserved renal function (serum creatinine levels lower than 2.5 mg/dl). KT patients were on immunosuppressive therapy and the cumulative doses of these drugs were also evaluated. BMD was determined by dual-energy X-ray absorptiometry at multiple sites (spine, femur and total body). Quantitative ultrasound of the calcaneus (broadband ultrasound attenuation, speed of sound, and stiffness index, SI) was also performed. Twenty-four percent (46) of all patients had either vertebral (29/46) or appendicular (17/46) fractures. We found osteoporosis and osteopenia in 8.5-13.4 and 30.9-35.1% of KT patients, respectively. Women had more fractures than men. In women, prevalent fractures were associated with diabetes mellitus [OR = 11.5, 95% CI (2.4-55.7)], time since menopause [OR = 3.7, 95% CI (1.2-11.9)], femoral neck BMD [OR = 1.99, 95% CI (1.4-2.8)], cumulative dose of steroids [OR = 1.1, 95% CI (1.02-1.12)] and low SI [OR = 1.1, 95% CI (1.0-1.2)]. In men, fractures were associated with lower lumbar spine BMD [OR = 1.75, 95% CI (1.1-2.7)], lower SI [OR = 1.1, 95% CI (1.03-1.13)], duration of dialysis [OR = 1.3, 95% CI (1.13-2.7)], and lower body mass index [OR = 1.24, 95% CI (1.1-1.4). Our results demonstrate high prevalence of low BMD and osteoporotic fractures in patients receiving a successful kidney transplant and indicate the need for specific intervention to prevent osteoporosis in this population.

Evaluation of quality of butter from different provenance

Butter samples were evaluated for free fatty acids, peroxide value, cholesterol, and fatty acid composition focusing on the trans isomer and conjugated linoleic acid (CLA). Sixty six samples were analyzed. Thirty six were collected in Brazil, eighteen in France, and twelve in Argentina. Samples were evaluated by free fatty acids, peroxide value, total lipid, cholesterol and fatty acid composition. The free fatty acid content varied from 0.16 to 0.46 g.100 g-1 and the peroxides value levels from 0.35 to 1.80 meq.kg-1. The cholesterol content varied from 192.8 to 226.3 g.100 g-1 and the total lipid content varied from 81.8 to 86.8 g.100 g-1. The levels of saturated, monounsaturated, and polyunsaturated fatty acids varied from 43.86 to 52.74, from 21.65 to 23.34, and from 2.11 to 2.89 g.100 g-1, respectively. The conjugated linoleic acid (CLA) content varied from 0.56 to 0.86 g.100 g-1 and the levels of total trans isomer varied from 2.18 to 3.81 g.100 g-1.

Variações nos níveis de adiponectina nos pacientes com doença renal crônica: um estudo prospectivo de 12 meses

INTRODUÇÃO: As complicações cardiovasculares permanecem como a principal causa de mortalidade nos pacientes portadores de doença renal crônica (DRC). A adiponectina é uma proteína produzida pelo tecido adiposo que apresenta importante propriedade cardioprotetora. O nosso objetivo foi investigar os determinantes dos níveis de adiponectina nos pacientes com DRC. MÉTODOS: Este estudo prospectivo observacional incluiu 98 pacientes [taxa de filtração glomerular (TFG) 36,1+-14,4 ml/min; 56,5+-10,4 anos; 63% homens; 31% diabéticos e índice de massa corporal (IMC) 27,1+-5,2 kg/m²]. A avaliação da adiponectina (teste imunoenzimático), dos parâmetros laboratoriais, do estado nutricional (avaliação global subjetiva), da gordura corporal total (absortometria de raios-x de dupla energia) e da gordura abdominal visceral e subcutânea (tomografia computadorizada) foi realizada no início e após 12 meses. RESULTADOS: A adiponectina correlacionou-se com a TFG (r = -0,45; p < 0,001), a proteinúria (r = 0,21; p = 0,04), o IMC (r = -0,33; p < 0,01) e a gordura visceral (r = -0,49; p < 0,001). Na análise de regressão múltipla, os determinantes das concentrações de adiponectina foram o sexo (feminino β = 3,8; p < 0,01), a idade (β = 0,14; p = 0,03), a TFG (β = -0,15; p < 0,01) e a gordura visceral (β = -0,04; p < 0,001) (R² = 0,41). Após 12 meses, a progressão da DRC foi evidenciada pela diminuição da TFG (-1,6+-6,3 ml/min; p = 0,01) e aumento da proteinúria (0,3+-0,8 g/d; p < 0,01). Houve um aumento da gordura visceral de 97+-73 cm² para 111+-82 cm² (p < 0,001) e concomitante redução dos níveis de adiponectina, de 27,6+-7,5 mg/l para 22,2+-11,6 mg/l (p < 0,001). O peso corporal, o IMC, a gordura corporal total e a gordura abdominal subcutânea não se alteraram neste período. Ajustando pelos fatores associados à adiponectina, observamos que somente o acúmulo de gordura visceral ao longo do tempo determinou a redução nos níveis de adiponectina (β = -0,04; p = 0,025; R² = 0,21). CONCLUSÃO: A idade, o sexo, a função renal e a gordura visceral estiveram independentemente associados com os níveis de adiponectina nos pacientes com DRC na fase não dialítica. No entanto, a mudança da gordura visceral foi o único preditor das variações nos níveis de adiponectina ao longo de 12 meses.

Espironolactona reduz a pressão arterial e a albuminúria de hipertensos obesos com síndrome metabólica

INTRODUÇÃO: A aldosterona tem sido implicada na fisiopatologia da síndrome metabólica (SM), assim como da hipertensão arterial a ela associada; entretanto, o uso de antagonistas do receptor mineralocorticoide neste grupo de indivíduos foi pouco estudado. OBJETIVOS: Avaliar os efeitos do bloqueio mineralocorticoide no comportamento pressórico, em parâmetros metabólicos, inflamatórios e renais de indivíduos com SM. MÉTODOS: Vinte e nove indivíduos com SM foram avaliados em estudo prospectivo que consistiu de dois períodos: basal (duas semanas), no qual foram obtidos dados demográficos e suspensa a medicação anti-hipertensiva, e período de tratamento, no qual foi administrada espironolactona (25 a 50 mg/dia), por 16 semanas. Em ambos os períodos, foram avaliados marcadores inflamatórios, metabólicos e renais, além da realização da monitorização ambulatorial da pressão arterial. RESULTADOS: Após tratamento com espironolactona, a pressão arterial sistólica e diastólica de 24 horas reduziu de 143,5 ± 15,17 mmHg para 133,2 ± 17,34 mmHg (p = 0,025) e de 85,2 ± 11,10 mmHg para 79,3 ± 11,78 mmHg (p = 0,026), respectivamente. Os níveis de colesterol HDL aumentaram de 44,0 ± 8,67 para 49,0 ± 6,75mg/dL (p = 0,000) e a proteína C reativa reduziu significantemente de 6,3 ± 7,54 mg/L para 4,6 ± 6,30 mg/L. Os níveis de glicemia de jejum, insulina, HOMA-IR e triglicérides não apresentaram alteração significante após bloqueio do receptor mineralocorticoide. A filtração glomerular estimada não se alterou, enquanto o logaritmo da albuminúria reduziu significantemente de 2,5 ± 0,92 para 2,0 ± 0,95. CONCLUSÃO: A administração de espironolactona em monoterapia a hipertensos com SM foi eficaz no controle da hipertensão arterial, reduziu a excreção urinária de albumina e elevou os níveis de colesterol HDL.