Assuntos
Exercício Físico , Idoso , Índice de Massa Corporal , Chile , Tolerância ao Exercício , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Caminhada , Suporte de CargaRESUMO
OBJECTIVE: There is a seasonal variation in the incidence of diabetes mellitus and cardiovascular diseases. However, there is very little information about the seasonal variation in insulin sensitivity. We report the seasonal variation in insulin sensitivity in a group of elderly subjects followed for 1 y. METHODS: Healthy elderly (>/=70 y) subjects living independently were included. Fifty percent of subjects received a daily nutritional supplement that provided 400 kcal, 15 g of protein, and 50% of vitamin daily reference values (DRVs). Those receiving and not receiving supplements were randomly assigned to a resistance exercise training program. Every 6 mo (winter, summer, and winter), body composition was measured by dual-energy x-ray absorptiometry and blood samples were used to measure serum lipids, fasting and postprandial glucose, and insulin levels. RESULTS: One hundred eight subjects (31 supplemented and trained, 28 supplemented, 16 trained, and 33 without supplementation or training) completed the follow up. Higher homeostasis assessment of insulin sensitivity, postprandial insulin, and fasting triacylglycerol levels were observed during the summer than during the winter. Body fat increased steadily during the study period, and fat-free mass did not change. Serum low-density lipoprotein cholesterol decreased significantly in the supplemented and trained group and increased in the non-intervention group. CONCLUSIONS: In this group of elderly subjects, insulin resistance and triacylglycerol levels were higher during the summer. Nutritional supplementation and training had a positive effect on serum low-density lipoprotein cholesterol.
Assuntos
Envelhecimento/fisiologia , Doenças Cardiovasculares/sangue , Diabetes Mellitus Tipo 2/sangue , Exercício Físico/fisiologia , Insulina/metabolismo , Vitaminas/administração & dosagem , Absorciometria de Fóton , Idoso , Composição Corporal/efeitos dos fármacos , Composição Corporal/fisiologia , Doenças Cardiovasculares/epidemiologia , LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Suplementos Nutricionais , Jejum , Feminino , Humanos , Incidência , Masculino , Período Pós-Prandial , Estudos Prospectivos , Estações do Ano , Triglicerídeos/sangueRESUMO
OBJECTIVES: To compare endothelium-dependent vasomotor response in healthy younger and older subjects without classic cardiovascular risk factors, with high and normal fasting homocysteine (tHcy) levels. DESIGN: We compared endothelium-dependent vasodilatation, using ultrasound, in healthy younger (aged 18-40) and older (> or =70) people with normal (<13 micromol/L) and high (>15 micromol/L) tHcy levels. Exclusion criteria were smoking, personal history of cardiovascular disease, hypertension, chronic diseases, vitamin intake, obesity, abnormal serum lipids levels, and creatinine higher than 130 micromol/L. SETTING: Research laboratory. MEASUREMENTS: In addition to tHcy levels, serum folate and vitamin B12 levels were measured. RESULTS: We studied 17 younger and 12 older hyperhomocysteinemic subjects and respective aged-matched normohocysteinemic subjects. Endothelium-dependent vasodilatation was lower in the hyperhomocysteinemic older people (P <.01) than in all younger subjects and in normohomocysteinemic older people. Serum vitamin B12 levels were higher in younger and older normal controls. Folic acid levels were higher in younger controls and in both older groups. CONCLUSIONS: This study shows an effect of high circulating tHcy on vascular reactivity in older people. Because serum levels of tHcy are associated with nutritional status of vitamin B12 and folic acid, prospective studies are necessary to demonstrate the effects of a long-term nutritional supplementation with vitamins on vascular function and global cardiovascular risk.
Assuntos
Endotélio Vascular/fisiologia , Homocisteína/sangue , Vasodilatação/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Feminino , Ácido Fólico , Humanos , Masculino , Vitamina B 12/sangueRESUMO
OBJECTIVE: The incidence of protein-calorie malnutrition in hospitalized adult patients can reach 30% to 50% and adversely affect clinical outcome. We evaluated the efficacy of muscle strength to predict functional derangement and detect early changes in nutrition status in hospitalized patients. METHODS: Patients hospitalized at medical and surgical wards from two different hospitals in Santiago, Chile, were studied during their hospital stay. Subjective Global Assessment of nutrition status and laboratory parameters were measured on admission. Anthropometric measures, handgrip dynamometry, and maximal inspiratory and expiratory pressures were measured on admission and discharge. The Karnofsky index was used to assess functional status. Twice weekly, caloric balance was calculated with indirect calorimetry and assessment of dietary intake. RESULTS: From the initial selection of patients (n = 70), 50 patients (26 men and 24 women) completed the study. Median hospital stay was 10 d. Subjective Global Assessment was associated with anthropometric data, handgrip dynamometry, and serum levels of total proteins. Patients in whom functional status declined during hospital stay, on admission had lower left handgrip strength, a worse Subjective Global Assessment classification, were older, and had lower fat mass. No association between caloric balance during hospital stay and changes in muscle strength was observed. CONCLUSIONS: Subjective Global Assessment, handgrip strength, and fat mass were good predictors for the decline in functional status during hospital stay. No association between caloric balance and changes in muscle strength was observed.
Assuntos
Hospitalização , Debilidade Muscular , Estado Nutricional , Adulto , Idoso , Antropometria , Feminino , Força da Mão , Humanos , Medidas de Volume Pulmonar , Masculino , Pessoa de Meia-Idade , Desnutrição Proteico-Calórica/diagnóstico , Desnutrição Proteico-Calórica/epidemiologia , Testes de Função RespiratóriaRESUMO
Hyperhomocysteinemia is considered a risk factor for cardiovascular disease and is prevalent in the elderly. Supplementation with folic acid, vitamin B-6 and B-12 lowers homocysteine levels. In January 2000, the Chilean government initiated a flour folic acid fortification program to decrease the occurrence of neural tube defects. The aim of this study was to evaluate the effect of this program on serum homocysteine and folate levels in elderly subjects after 6 mo. A total of 108 elderly people were studied. We measured serum folate, homocysteine and vitamin B-12 levels before the fortification started and 6 mo later. At baseline, folate deficiency (<6.8 nmol/L) was present in 1.8%, vitamin B-12 deficiency (<165 pmol/L) in 27.6% and hyperhomocysteinemia (>14 micromol/L) in 31% of the sample. Six months later, serum folate levels increased from 16.2 +/- 6.2 to 32.7 +/- 7.1 nmol/L (P < 0.001), homocysteine levels decreased from 12.95 +/- 3.7 to 11.43 +/- 3.6 micromol/L (P < 0.001) and vitamin B-12 levels were unchanged. Flour fortification with folic acid had a moderate lowering effect on homocysteine levels. Given that vitamin B-12 deficiency was more common than folate deficiency, it may be more appropriate to add vitamin B-12 to food, at least in foods for this age group.