[Methods to estimate body composition in the elderly: a critical analysis]. / Métodos de estimación de la composición corporal de ancianos: análisis crítico.

The objective of this study was to compare the values obtained for total body fat obtained with deuterium dilution, anthropometry and bioimpedance in 41 institutionalized elderly individuals (65-90 years old). The values obtained with each technique were compared using the graphic analysis proposed by Bland and Altman, that plots the difference between measurements with both methods against their average. In men (n = 20) and women (n = 21), the best degree of agreement was obtained between the values measured by deuterium dilution and those calculated from skinfolds (mean difference = 1.4% and 6.9%, respectively). The limits of agreement (+/-2SD), for skinfolds reached a maximum of 14.8% in men, and 16.8% in women. These values tend to underestimate fat in the obese and overestimate it in thinner subjects. For bioimpedance and deuterium dilution, the inter-method difference is significantly greater: 9.3% in men and 14.7% in women. This lack of agreement is attributed to the fact that the bioimpedance equipment utilizes equations validated for younger adults. In conclusion, estimation of body composition using skinfoids has the smallest difference compared to deuterium dilution, even though individual measurements are not clinically acceptable. Caution is recommended when using measurements of body composition in the elderly, due to large errors in the determinations.

[Cardiovascular risk factors in healthy adult men: influence of physical activity and dietary habits]. / Factors de riesgo cardiovascular en hombres adultos sanos: influencia de la actividad física e ingesta dietaria.

OBJECTIVE: To study the influence of physical activity and certain dietary habits on cardiovascular risk factors in middle age men. DESIGN: Prospective cross sectional study. SETTING: Primary care. SUBJECTS: Healthy male workers participating in a preventive medical examination. INTERVENTIONS: All participants were subjected to a physical activity inquiry, dietary recall, inquiry about smoking habits and anthropometric assessment. Also, blood pressure was measured and a fasting blood sample was obtained to assess serum total and HDL cholesterol, triglycerides and blood glucose. Multiple stepwise and canonical regressions were used to analyze data. RESULTS: Four hundred eleven subjects aged 46.8 +/- 10 years old were studied. Twenty four percent smoked, mean body mass index was 26.2 +/- 2.6, mean calorie intake was 11.7 +/- 3 MJ/day and mean calorie expenditure 10.6 +/- 1.1 MJ/day or 1.52 +/- 0.13 times the resting metabolic rate. Physical activity, body mass index and fiber intake appeared as independent but weak predictors of total and LDL cholesterol. Alcohol intake, age and body mass index were predictors of HDL cholesterol and blood pressure was predicted by age, fiber intake and body mass index. Canonical analysis showed that 54% of blood pressure variation is explained by age, body mass index and fiber intake and that 31% of HDL cholesterol variation is explained by alcohol intake. CONCLUSIONS: Physical activity has a weak influence on serum total and LDL cholesterol. Alcohol intake is the main predictor of HDL cholesterol in these workers.

[Influence of body fat and its distribution on cardiovascular risk factors in healthy subjects]. / Influencia de la grasa corporal y su distribución sobre factores de riesgo cardiovascular en sujetos sanos.

The aim of this work was to study the association between obesity and body fat distribution with known cardiovascular risk factors. Seven hundred eighty two healthy individuals, 634 men and 148 female age 44 +/- 10 years were studied. Multiple stepwise regression models were performed in which cardiovascular risk factors (total, LDL and HDL cholesterol, triglycerides, fasting and postprandial blood glucose, systolic and diastolic blood pressure) were considered as the dependent variable and age, sex, smoking habits, body mass index (BMI), waist circumference (WC), waist hip ratio (WHR), subscapular/tricipital skinfold ratio (STR) and percentage of total body fat (%BF), derived from the sum of four skinfolds, as the independent variables. Among anthropometric variables, WC was the principal predictor of total cholesterol and basal blood glucose, WHR was the principal predictor of HDL cholesterol (inverse relationship) and triglycerides; BMI was the principal predictor of systolic and diastolic blood pressure; %BF was the principal predictor of post prandial blood glucose. Performing the same analysis in a subgroup of patients with a BMI between 21 and 24, measures of fat distribution continued to be predictors of cardiovascular risk factors. It is concluded that both total body fat and its distribution are related to cardiovascular risk factors and, in some cases, may have an additive effect and should be measured in preventive medical examinations.

[A 2-year follow-up of a program for the control of cardiovascular risk factors among asymptomatic workers]. / Evaluación a dos años de un programa de control de factores de riesgocardiovascular en trabajadores asintomáticos.

In 1987, a cardiovascular risk profile was obtained on 836 workers of the National Electricity Co in Santiago. There were 714 males and 125 females, the mean age was 45 years (ES +/- 0.3). Hypertension (systolic pressure > 160 or diastolic > 90 mmHg) was present in 17% of subjects, hypercholesterolemia (> 240 mg/dl or > 220 mg/dl associated to 2 other risk factors) in 17%, obesity (> 20% above ideal weight) in 33% and 29% were smokers. An advice to stop smoking, changes in the casino menu and hypertension, obesity and hypercholesterolemia's control programs were offered. These were attended by 108 hypertensives, 141 subjects with hypercholesterolemia and 104 obese individuals with an attendance rate of 64%, 75 and 77% respectively. Measurements repeated 2 years later revealed a reduction in diastolic pressure of 3.3 +/- 1.1 mmHg (p < 0.004) only in adherent subjects. Cholesterol levels were reduced by 24 +/- 3 mg/dl (p < 0.001) with no differences for non participants, adherent and non adherent subjects. Adherent obese subjects reduced their weight by 2.2 +/- 0.4 kg (p < 0.001). There was no change in the number of smokers.

[Microalbuminuria after unilateral nephrectomy in humans: study of effects of dietary protein]. / Microalbuminuria postnefrectomia unilateral en humanos: estudio del effecto del contenido habitual de proteina de la dieta.

Microalbuminuria may be due to increased glomerular capillary pressure. In turn, this increased pressure may be associated to augmented protein intake or reduction of renal mass. 85 normal subjects who had a unilateral nephrectomy were studied. Creatinine clearance, microalbuminuria and blood pressure were measured. Hyperfiltration was evaluated by comparison of creatinine clearance before and after nephrectomy. Protein intake was evaluated by a nutritional questionnaire. Hyperfiltration was estimated as 38% and microalbuminuria was not different in patients submitted to nephrectomy (9.8 micrograms/min) compared to controls (9.7). Microalbuminuria post nephrectomy was not correlated to level of hyperfiltration, protein intake, age, blood pressure or time after surgery. These results suggest that the remaining kidney is able to double the excretion of albumin with a likely increase in glomerular filtration and intracapillary pressure.

[Preventive medical examination in asymptomatic workers: design and initial outcome of an institutional program]. / Examen médico preventivo en trabajadores asintomáticos: diseño y resultados iniciales de un programa institucional.

We have designed a preventive medical examination program for workers of an electric company in Santiago, Chile. The first stage, directed mainly to identification of cardiovascular risk factors was completed in 1987. 1006 males and 163 females with mean age 45 +/- 9.4 years (range 22-65) were screened. High blood pressure mainly of mild degree was detected in 17.6% of subjects (57% of them were new cases). Total cholesterol above 220 mg/dl and HDL cholesterol below 40 mg/dl were present in 33% and 22%, respectively. Obesity (body weight > 120% of ideal weight for height) was present in 19%, and body mass index was above 27 in 25% of subjects. 23% of males and 31% of females smoked 1 or more cigarettes a day and 2% had an abnormal non-fasting glucose level. A total of 750 workers have at least 1 risk factor that should be corrected. No cases of cancer were detected by Papanicolaou and mammography. A positive correlation was found among LDL cholesterol, age and triglyceride levels and HDL was negatively correlated to triglycerides, blood glucose and obesity. A multivariate analysis of these factors revealed that only age was related to LDL levels and triglycerides to HDL levels. This health prevention program may help a significant number of asymptomatic workers by detecting risk factors that need correction in order to decrease mortality and morbidity in this population.

[Treatment of chronic renal failure: effects of a supplemented diet with essential amino acids]. / Tratamiento de la insuficiencia renal crónica: efectos de una dieta suplementada con aminoácidos esenciales.

We evaluated the results of essential amino acids supplementation added to a protein restricted diet (0.6 g/kg/day) in patients with advanced renal failure (creatinine clearance under 20 ml/min). A diet containing food with high biologic value was used as control. Diets were tested during 7 months. Anthropometric and nutritional (serum albumin and transferrin) values were normal in both groups both at the beginning and at the end of the treatment period. A slight increase in weight in the natural diet group and in serum phosphorus level in the amino acid supplemented group was observed. Two patients in each group required chronic dialysis, renal function remaining stable in the rest. We conclude that both forms of diet supplementation were effective in preserving nutritional status possibly in delaying deterioration of renal function in patients with advanced renal failure.

Nutritional support in hospitalized patients with alcoholic liver disease.

The effects of a nutritional support in hospitalized patients with alcoholic cirrhosis and liver failure were studied in a controlled protocol. Thirty-six patients were included, 17 were randomly assigned to an experimental group and the rest to a control group. Experimentals received a diet aiming at 50 kcal (209 kJ)/kg bodyweight/d and 1.5 g protein/kg bodyweight/d (as proteins of high biological value). Controls received the standard diet prescribed by the attending physician. The severity of liver failure and the nutritional status on admission were similar in both groups. The measured energy intake in controls was 1813 +/- 121 kcal/d (7589 +/- 506 kJ/d) and 2707 +/- 71 kcal/d (1131 +/- 297 kJ/d) in experimentals (P less than 0.001). The protein intake in controls was 47 +/- 3.8 g/d and in experimentals 80 +/- 3 g/d (P less than 0.001). There were seven deaths during the study period (two experimentals and five controls). No differences were observed in the evolution of liver failure, hepatic encephalopathy or nutritional status between both study groups. It is concluded that a higher energy and protein intake in these patients does not have adverse effects and is associated with a non-significant reduction in mortality.