Importancia de la leche en la nutrición del adulto mayor / Importance of milk in elderly nutrition

El proceso de envejecimiento es un fenómeno complejo que abarca cambios moleculares, celulares, fisiológicos y psicológicos. Los adultos mayores son especialmente susceptibles a presentar problemas nutricionales, tanto por alteraciones gastrointestinales, como por cambios en los requerimientos de nutrientes, alteraciones en la sensación del gusto, deterioro en la dentición, uso de medicamentos, depresión, aislamiento social y pobreza, siendo esta última la más importante causa de malnutrición en este grupo etáreo. En la mayor parte de la población el consumo de alimentos saludables se encuentra muy limitado, no alcanzando a cubrir los requerimientos de proteínas, minerales y micronutrientes. Una alimentación saludable, variada, con buen aporte proteico y de micronutrientes, manteniendo una adecuada actividad física es fundamental para tener una mejor calidad de vida. Dentro de una alimentación saludable, la leche cumple un papel fundamental por su aporte de proteínas y nutrientes esenciales, dentro de los cuales se destacan las vitaminas B1, B2 y minerales como calcio y fósforo

Estado nutritivo y gasto energético en ancianos de distinto nivel socioeconómico / Nutritional status and energy expenditure in elders of differing socioeconomic level

Background: Income and socioeconomic status can influence nutritional status of individuals. Since elders are a more vulnerable group to nutritional deficiencies, socioeconomic status could have a special relevance on nutrition of elderly people. Aim: To assess the influence of socioeconomic status on the nutritional status of elders. Material and methods: Elders of both sexes of high socioeconomic level and age and sex matched elders of low socioeconomic status were studied. Anthropometry, body composition using double beam X ray absorptiometry, resting energy expenditure using an open circuit indirect calorimeter, routine biochemistry, blood levels of folic acid, vitamin B12 and homocysteine were measured in all subjects. Results: Fourteen female elders of high socioeconomic level, 14 females of low level and 12 males of each level were studied. Mean age of females and males was 71.5 ñ 3.7 and 73.9 ñ 4.2 years old respectively. Males and females of high socioeconomic status were taller than their counterparts of low status. Females of high socioeconomic status had a lower body mass index than their pairs of low status (26.3 ñ 3.8 and 30.2 ñ 5.6 kg/m2 respectively p <0.02). Men of high economic status had a higher fat mass than their pairs of low level (20.3 ñ 3.5 and 15.1 ñ 5.5 kg respectively, p <0.005). No differences in resting energy expenditure in women of differing socioeconomic level were observed. Men of high level had a higher energy expenditure than their counterparts of low level (36.0 ñ 4.9 and 32.8 ñ 2.2 Kcal/kg lean body mass/day respectively, p<0.02). Low level male elders had higher serum total cholesterol and triglycerides. Folic acid, vitamin B12 and homocysteine levels were within normal limits. Dietary intake showed deficiencies in calorie, protein and vitamin intake in all subjects. Conclusions: In this group of elders, low socioeconomic level did not produce a significant impact on nutritional status

Nutrición y envejecimiento / Nutrition and aging

Genetic and environmental factors influence the process of aging. Longevity is extraordinarily constant along species and there are several genes that regulate it. Special consideration deserve apoprotein E alleles, specially allele eee4 that is associated with development of Alzheimer disease, atheroesclerosis and a shorter life. However environmental influences on longevity are of utmost importance. In rats, mice and non human primates, caloric restriction prolongs life and retards the appearance of several conditions associated with aging. This effect of caloric restriction is probably due mainly to a reduction in the generation of primary and secondary reactive oxygen species. Noteworthy is the reduction of DNA oxidative damage and the consequent reduction in transcriptional defects. Telomeres, special structures located in the extremes of chromosomes, are specially susceptible to oxidative damage. This structures have been postulated to act as biological clocks of cells, since their progressive shortening is a signal to stop replication. In humans, telomeres shorten throughout life and in some diseases associated with premature aging such as trisomy 21 and Werner syndrome, the loss of telomeric bases occurs at a higher rate. The knowledge about environmental influences on aging will allow us to increase our life span and to reduce the disabilities associated with aging

Niveles de homocisteína en adultos sanos chilenos / Serum homocysteine levels in healthy chilean adults

Background: Hyperhomocysteinemia is a newly recognized cardiovascular risk factor that is present in 10 to 20percent of European and North American individuals. Aim: To measure homocysteine levels in healthy adults in Chile. Subjects and methods: Serum homocysteine levels were measured in healthy adults using a fluorimetric HPLC method. Folic acid, vitamin B12, serum lipids, creatinine and glucose were also assessed. All subjects answered a dietary habits questionnaire. Results: One hundred twenty eight subjects (90 female) aged 22 to 78 years old were studied. Homocysteine levels were 9.7 ñ 6.0 and 7.0 ñ 3.1 µmol/l in men and women respectively (p< 0.001). Folic acid levels were 6.1 ñ 2.7 and 6.1 ñ 2.9 ng/ml in men and women, and 24percent of individuals had values below 4 ng/ml. Vitamin B12 levels were 393 ñ 147 and 393 ñ 163 pg/ml in the same groups. There was a negative correlation between homocysteine and folic acid levels and a positive correlation between homocysteine and creatinine levels. Conclusions: Homocysteine levels in healthy Chilean individuals are similar to those reported abroad. Low folic acid levels were found in 24percent of subjects

Influencia de factores de riesgo y terapia farmacológica en la mortalidad de hipertensos esenciales / Influence of pharmacological treatment and risk factors on mortality of hypertensive patients

Background: The V JNC consensus stated that although new antihypertensive agents, such as angiotensin converting enzyme inhibitors and calcium channel blockers, are considered safer drugs, there is no firm evidence from large controlled trials that these drugs are associated with a lower cardiovascular mortality. Aim: To study the association between cardiovascular risk factors, blood pressure levels, pharmacological treatment and mortality in a group of hypertensive patients followed at an hypertension outpatient clinic. Patients and methods: Patients with essential hypertension were treated with different antihypertensive medications, according to physicians criteria, and controlled until death or loss from follow up. Causes of death were obtained from hospital records and death certificates. Survival was analyzed using life tables, comparisons between groups of patients were done using chi square or a Cox's proportional hazards model. Results: Three hundred thirty nine hypertensive patients aged 33 to 80 years old were followed for a mean period of 9.8 ñ 4.9 years. Eighty six were treated with beta blockers, 64 with diuretics, 133 with calcium antagonists and 56 with ACE inhibitors. Blood pressure dropped similarly with all medications. During follow up, 79 patients died. Life table analysis showed that patients with a history of angina, diabetes or myocardial infarction had higher mortality rates. Similarly, patients treated with beta blockers and diuretics had higher mortality than patients treated with calcium antagonists or angiotensin converting enzyme inhibitors. The proportional hazards model showed that the effect of treatment modality persisted after correction for the other risk factors for mortality. Conclusions: In this series of hypertensive patients, those treated with beta blockers or diuretics had higher mortality rates than those receiving calcium channel antagonists or angiotensin converting enzyme inhibitors

Artículos biomédicos de autores chilenos publicados en revistas extranjeras durante 1997: una revisión del MEDLINE / Biomedical papers by chilean authors published in international journals during 1997: a selection from MEDLINE

Background: Many Chilean biomedical investigators publish the results of their research in international journals, not easily accesible to fellow physicians of the country. Aim: To assess the amount and quality of papers published by Chilean authors in international journals. Data source and methods: Using Medline databases from January to August, 1997, all papers in which Chile appeared in the field "AD" (Address of author) were selected. Papers with a clear relationship to human medicine were identified. Results: During the study period, 390 papers with authors residing in Chile appeared in Medline. Of these, 188 (48 per cent) were published in Chile and the rest was published abroad. Thirty manuscripts had a greater relationship to clinical medicine and the authors of nine of them were invited to submit a translation of their abstract into Spanish to have them reproduced in the present article. Conclusions: A significant proportion of biomedical research papers originated in Chile is published abroad with the consequent lack of diffusion among non-specialized readers from their own country

Permeabilidad intestinal en alcohólicos sin daño hepático / Intestinal permeability in alcoholics without hepatic damage

Methods: Thirty seven male subjects were studied, 18 controls and 19 alcoholic: All subjects underwent an anthropometric assessment and dietary history. Lactulose/mannitol test was performed during the third day of abstinence in alcoholics. After an 8 hour overnight fast, subjects drank 200 ml of a solution containing 56 g lactulose and 5 g mannitol. Subsequently, urine was collected during the following 5 hours, where both sugars were measured by gas chromatography. Results: Median values of lactulose/mannitol ratio were similar in alcoholics and controls (0.011, range 0.005-0.071 vs 0.014, range 0.005-0.027 respectively). However, absolute urinary excretion of both lactulose and mannitol was lower in alcholics. There was no relationship betwwen nutritional status and urinary excretion of lactulose, mannitol or lactulose/mannitol ratio. Conslusion: In this alcoholic patients, no changes were observed in intestinal permability

Marcadores de fibrogénesis hepática en pacientes alcohólicos / Hepatic fibrogenesis markers in alcoholic patients

Serum P-III-P and laminim levels were measured in asymptomatic alcoholics during detoxication treatment. Liver biopsies were obtained, in order to detect liver damage, which was graded with a numeric score, considering values over 6 as severe damage. Serum fibrogenesis markers were also measured in a group of decompensated alcoholic cirrhotics. P-III-P levels were significantly higher in cirrhotic patients compared to alcoholics with or without liver damage and to normal controls. Laminin was not different between groups. P-III-P did not correlate with histological score in asymptomatic patients. In this study P-III-P and P1 laminin were not usefull discriminators of severe liver damage among asymptomatic alcoholics; their levels were found to rises significantly only when liver disease has become clinically evident

Métodos de estimación de la composición corporal de ancianos: análisis crítico / Body composition estimation methods in elderly: critical analysis

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 agreements was obtained between the values measured by deuterium dilution and those calculated from skinfolds (mean difference=1.4 percent and 6.9 percent respectively). The limits of agreement (ñ2SD) for skinfolds reached a maximun of 14.8 percent in men, and 16.8 percent 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 percent in men and 14.7 percent 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 skinfolds has the smallest difference compared with deuterium dilution, eventhougt individual measurements are not clinically acceptable. Caution is recommended when using individual measurements of body composition in the elderly, due to large errors in the determinations

Factores de riesgo cardiovascular en hombres adultos sanos: innfluencia de la actividad física e ingesta dietaria / Cardiovascular risk factors in adult healthy men: influence of physical activity and dietary intake

To study the influence of physical activity and certain dietary habits on cardiovascular risk factors in middle age men, healthy male workers 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. Four hundred eleven subjects aged 46.8ñ10 years were studied. Twenty four percent smoked, mean body mass index was 26.4ñ2.6, mean caloric intake was 11.7ñ3 MJ/day and mean caloric expenditure 10.6ñ1.1 MJ/day or 1.52ñ0.13 times the resting metabolic rate. Physical activity, body mass index and fiber intake appreared as independent but weak predictor 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 percent of blood pressure variation is explained by age, body mass index and fiber intake and in 31 percent of HDL cholesterol variation is explained by alcohol intake. Physical activity has a weak influence on serum total and LDL cholesterol. Alcohol intake is the main predictor of HDL cholesterol in these workers

Pacientes con limitación crónica al flujo aéreo: efectos del entrenamiento muscular respiratorio con válvula de carga umbral construída con tecnología apropiada, asociado a apoyo nutricional / Patients with chronic airflow limitation: effects of muscular respiratory training with threshold load valve constructed according to appropriate technology, associated to nutritional support

To assess prospectively the effects of a controlled program of inspiratory muscle program and nutritional support in patients with chronic obstructive lung disease (COPD). 23 patients with COPD were randomly assigned into 4 groups. Group I received a 1000 kcal/day nutritional supplement, given as a casein based enteral nutritional formula; group III was subjected to inspiratory muscle training, using an inexpensive pressure threshold load valve constructed according to appropriate technology principles of the WHO, adjusted at 30 percent of Maximal Inspiratory Mouth Pressure and received also the nutritional supplement; group IV was trained but did not receive the nutritional supplement and group II was not trained nor supplemented. Patients were studied during 3 months and monthly, inspiratory muscle function, exercise capacity and antropometry were measured. A significant improvement in exercise capacity, maximal inspiratory pressure and inspiratory muscle endurance was observed in the 4 groups throughout the study. Trained subjects had greater improvement in their inspiratory muscle endurance, compared to untrained subjects. Nutritional support had no effect in inspiratory muscle function or exercise capacity. No changes in antropometric measures were observed. The pressure threshold load valve used in this study, improved inspiratory muscle endurance and nutritional support had no effect in patients with COPD