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Biomedical subjects

W C Hunt

Publications and source records attributed to W C Hunt.

At least 91 records · Page 5Linked to original sources
PubMed1987

Thyroid failure in the elderly. Microsomal antibodies as discriminant for therapy.

Thyrotropin (thyroid-stimulating hormone [TSH]) levels were elevated above 4.0 mU/L (microU/mL) in serum samples from 13.2% of 258 healthy elderly subjects. To investigate the natural history of progressive thyroid failure, serial thyroid functions were measured for four years in 26 of these subjects with elevated TSH levels. In one third of these subjects, biochemical thyroid failure developed (thyroxine level less than 58 nmol/L [4.5 micrograms/dL]) within the course of the study. All subjects with initial TSH levels above 20 mU/L (microU/mL), and 80% of those with high-titer thyroid antimicrosomal antibodies (regardless of initial TSH level), became overtly hypothyroid. Compared with subjects with high-titer antibody, those with antibody titer less than 1:1600 had lower TSH and higher thyroxine levels, and thyroid failure developed in none during the study. These results suggest that among older patients with isolated elevations of the TSH level, only those with markedly elevated TSH levels or high-titer antimicrosomal antibodies should be prophylactically treated with levothyroxine sodium replacement.

Aged↗
PubMed1987

Vitamin A intake and plasma retinol levels in healthy elderly men and women.

We examined intakes of vitamin A (diet plus supplement) and plasma retinol levels in a select group of elderly men (n = 90) and women (n = 110) on three separate occasions over a 4-y period. Median dietary levels remained at approximately 1400 retinol equivalents (RE) in men and 1250 RE in women. There were no time trends or gender differences noted in plasma retinol concentrations. Approximately 44% of the elderly men and women consumed an average of 2000 RE of a vitamin A supplement daily. Those taking supplement had a greater mean plasma retinol concentration than those not taking a supplement. This effect was greater in men than in women. A review of previous studies revealed that plasma retinol increases from a mean of approximately 35 micrograms/dL (1.22 mumol/L) at preschool age to a plateau of approximately 60 micrograms/dL (2.09 mumol/L) by age 40 y in men and 60 y in women.

Age Factors↗
PubMed1987

Daily multivitamin supplementation and vitamin blood levels in the elderly: a randomized, double-blind, placebo-controlled trial.

Despite the many questions being raised about multivitamin use by the elderly, it has not been proven that consuming an oral multivitamin alters vitamin blood levels in the aged. To address this question, we performed a randomized, prospective, placebo-controlled study of daily multivitamin supplementation in 101 noninstitutionalized ambulatory elderly persons (median age, 64 years). Vitamin levels were assayed at baseline, and at two and four months of supplementation. At four months, those taking multivitamins had statistically significant increased levels of water soluble vitamins (C, B2, B12, plasma, and erythrocyte folate) that were greater than changes noted for the placebo group. This was not true for fat soluble vitamins A and E. Greater storage pools of fat soluble vitamins help explain this discrepancy. We conclude that in the ambulatory elderly, oral multivitamins can raise levels of water soluble vitamins but the effect on fat soluble vitamins remains uncertain.

Administration, Oral↗
PubMed1987

Ascorbic acid intakes and plasma levels in healthy elderly.

The data presented show that elderly men have significantly lower plasma ascorbic acid concentrations than elderly women at similar intakes of ascorbic acid. We hypothesize that this difference is due to lower renal tubular reabsorption of ascorbic acid in elderly men. The finding that more than half of the healthy elderly men had plasma ascorbic acid levels less than 0.3 mg/dl with daily intakes of ascorbic acid in the range of 40 to 50 mg raises concern about the rationale of lowering the RDA for vitamin C from the current value of 60 mg to 40 mg for men and 30 mg for women. This recommendation is inconsistent with efforts to improve the health status of elderly Americans by assuring adequate intakes of all essential nutrients. Our data do not allow us to determine an optimal intake of ascorbic acid for the elderly. The possibility of increased health benefits associated with intakes that exceed the current RDA of 60 mg needs to be examined. We believe, however, that a prudent approach to both of these questions would be to recommend that elderly receive a daily ascorbic acid intake that would allow plasma concentration to be maintained at or near 1.0 mg/dl. The daily level of intake required to maintain this level would be approximately 125 mg and 75 mg in healthy elderly men and women respectively. These intakes would assure adequate body reserves of ascorbic acid.

Aged↗
PubMed1987

Survival of American Indian and Hispanic cancer patients in New Mexico and Arizona, 1969-82.

Survival was examined by ethnic group for 31,465 incident cancer cases diagnosed from 1969 through 1982 in Hispanic and non-Hispanic whites residing in New Mexico and in American Indians residing in New Mexico and Arizona. In comparison with the 1- and 5-year survival rates following the diagnosis of cancer for non-Hispanic whites, those for American Indians were generally poorer and, to a lesser extent, those for Hispanics were also poorer. The American Indian and Hispanic patients tended to have more advanced disease at the time of diagnosis, although this pattern was not consistent across all sites. For many primary cancer sites, American Indian patients were less likely to receive treatment for their cancer than were non-Hispanic whites. Hispanics were also less likely to be treated for cancers of some sites, although the differences were not as large as for American Indians. However, after adjustment for stage and treatment, American Indians demonstrated significantly poorer survival than non-Hispanic whites for cancers of many sites. After adjustment for stage and treatment, survival in Hispanics was generally comparable to that in non-Hispanic whites.

Age Factors↗
PubMed1986

Choice of cancer therapy varies with age of patient.

We used data on 22,899 cancer cases collected by the New Mexico Tumor Registry to examine the relationship between patient age and the use of potentially curative therapy for cancers of selected sites and acute leukemias. For cancers of most sites, either local or regional stage, the proportion of cases receiving potentially curative therapy declined with age. For local-stage cancers, the proportion not given any treatment increased with age. Overall mortality rates during the first year after diagnosis were much higher for local-stage cases without treatment than for those who received treatment. These data show that cancer therapy varies with age and suggest that decision making regarding therapy is influenced by the presence of other diseases.

Adult↗
PubMed1986

Ascorbate in plasma as measured by liquid chromatography and by dichlorophenolindophenol colorimetry.

Ascorbic acid was measured in 125 plasma samples by an automated colorimetric method involving dichlorophenolindophenol and by a "high-performance" liquid-chromatographic procedure with electrochemical detection. The two methods gave comparable results for samples with ascorbate concentrations of 1 to 20 mg/L (r = 0.97). We also measured the amount of total ascorbate (ascorbic acid + dehydroascorbic acid) in the same samples by a liquid-chromatographic procedure with precolumn derivitization of ascorbic acid. We confirmed that plasma contains little dehydroascorbic acid.

2,6-Dichloroindophenol↗
PubMed1985

Relationship between zinc intake, physical activity, and blood levels of high-density lipoprotein cholesterol in a healthy elderly population.

We investigated the relationship between level of exercise, ingestion of zinc supplements, and serum high-density lipoprotein (HDL) cholesterol levels in 270 healthy men and women over age 60. After controlling for sex, alcohol intake, and body mass, there was a significant positive correlation between level of exercise and serum HDL cholesterol in the 180 subjects not taking supplemental zinc (r = 0.26, P = .005) but not for those subjects taking supplemental zinc (r = -0.18, P = .14). Multiple regression analysis showed a significant interaction of zinc intake and activity level on HDL cholesterol (P = .04). In 22 subjects who were ingesting greater than 15 mg of supplemental, elemental zinc daily, cessation of zinc supplements for 8 weeks was associated with a significant increase in HDL cholesterol levels (2.0 mg/dL; P = .04). The change in HDL after stopping zinc was positively correlated with the level of exercise of the subjects (r = .41, P = .05). Thus supplemental zinc ingestion appears to block the exercise-induced increase in serum HDL cholesterol in a healthy population.

Aged↗
PubMed1984

Folate and vitamin B12 status in a healthy elderly population.

Folic acid and vitamin B12 nutritional status was examined in a group of 270 healthy elderly individuals using both dietary and biochemical measures. Of these 40 per cent had dietary intakes of folic acid that were less than half the recommended dietary allowance of 400 micrograms/day, and 13 per cent had intakes of less than half the recommended dietary allowance for vitamin B12 (3 micrograms/day). However, only 8 per cent had low plasma folates (less than 3.0 ng/ml) and only 3 per cent had RBC folates less than 140 ng/ml. Plasma true cobalamin levels less than 220 pg/ml were found in 3 per cent. None of these individuals showed any clinical signs of folate and/or vitamin B12 deficiency, and mean corpuscular volumes were not significantly greater than those for the entire population (90.8 +/- 4.1 fl). The correlations of intakes of folic acid and vitamin B12 with plasma or erythrocyte levels were moderate (about 0.5). It was also clear that those taking supplements had significantly greater blood levels than those not taking supplements, although the benefit of higher plasma or erythrocyte levels of these nutrients is not clear. The data indicate that folate and vitamin B12 status in free-living healthy elderly is not a major medical problem.

Aged↗
PubMed1984

Differences between right and left arm blood pressures in the elderly.

Recommendations vary on whether blood pressures should be measured in the right or in the left arm because no frequency distributions for a pressure difference between the arms exist. We took a total of 12 blood pressure determinations in both arms of 174 elderly persons and analyzed the data by a least-squares components of variance method. The mean difference between the arms (right minus left) was 0.93 mm of mercury for systole and 0.70 mm of mercury for diastole. For systole the proportion of persons having arm pressure differences exceeding 10 mm of mercury is 1.4% and that exceeding 7.5 mm of mercury is 6.5%. For most people, the pressure difference between the arms is small.

Aged↗
PubMed1983

Hearing acuity in a healthy elderly population: effects on emotional, cognitive, and social status.

Hearing acuity and the relationships between untreated hearing deficits and emotional state, cognitive functioning, and social integration were examined in 239 physically healthy, independent-living elderly men and women with a mean age of 72 years. Air-conduction, pure-tone thresholds in both ears were determined at high- and mid-frequencies, and participants were also given the Speech Perception in Noise test. Multivariate techniques were used to test for associations between hearing acuity and scores from the Kellner-Sheffield Symptom Questionnaire, the Jacobs Cognitive Screening Exam, the Halstead Category Test, the Wechsler Memory Scale, and the Interview Schedule for Social Interaction. No deleterious effects of untreated hearing deficits on emotional status or social integration were found. The findings suggest that those with a hearing loss perform less well on verbal but not on nonverbal tests of cognition.

Aged↗
PubMed1983

Iron status and anemia in the elderly: new findings and a review of previous studies.

Iron status was determined in 280 free-living and healthy elderly men (n = 131) and women (n = 149) by assessing dietary and supplemental iron intake as well as ten biochemical measures of iron nutriture (erythrocyte count, hemoglobin level, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, plasma iron level, total iron-binding capacity, per cent transferrin saturation, and ferritin level). Subject ages ranged from 60 to 93 years with a median age of 72 years for both women and men. For comparison purposes, iron status measures in an unselected group of younger men (n = 107) and women (n = 164) between the ages of 20 and 39 years were also obtained. None of the elderly women and only two (1.2 per cent) of the younger women had low hemoglobin levels (less than 12.0 g/dl). Three (2.3 per cent) of the elderly men and none of the younger men had low hemoglobin levels (less than 14 g/dl). Other iron status measures revealed that anemia or iron deficiency was no more prevalent in the healthy elderly population than in the younger adult population when identical criteria were used to assess iron nutriture. The genesis of anemia often seen in the elderly is not completely understood. Reported evidence suggests the presence of anemia in the elderly is a result of overall reduction of hematopoietic reserves. Because of the potentially serious consequences of this assumption about anemia to the treatment of the elderly, the authors critically review some of the studies that have been designed in the past to determine the prevalence and etiology of anemia in the aged. They suggest that health status, race, socioeconomic status, diet, and region are more important than age as explanations for the high prevalence of anemia seen in many previous studies.

Adult↗
PubMed1983

Vitamins, lipids and lipoproteins in a healthy elderly population.

Vitamin status may be related to serum lipid-lipoprotein levels. We tested this hypothesis in a group of 270 healthy elderly men and women over 60 years of age. Vitamin status was determined from dietary intakes and biochemical analysis of plasma. Fasting lipid profile included triglycerides, total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C). Correlations have been adjusted by partial correlation for age, physical activity, body mass index, and alcohol consumption. Neither vitamin E intake nor ascorbic acid intake nor ascorbic acid plasma levels correlated with any lipids measured. HDL-C levels did not correlate with any vitamin parameters. In men, vitamin A blood levels correlated with LDL-C, triglyceride, and total cholesterol levels. In women, total cholesterol levels correlated inversely with thiamine and riboflavin blood status and with dietary intake of vitamins B6, D, and niacin. LDL-C plasma values were also inversely correlated with both intake and plasma vitamin D levels and intakes of riboflavin and vitamin B12 in women.

Aged↗
PubMed1982

Nutritional status in a healthy elderly population: dietary and supplemental intakes.

Dietary and supplemental intakes were assessed from 3-day food records collected from 270 free-living, middle income and healthy men and women over 60 yr of age residing in the Albuquerque, NM vicinity. The 1980 Recommended Dietary Allowances (RDA) were used to assess adequacy of intake. Energy intake, as percentage of the RDA, was 90 +/- 23 (mean +/- SD) for men (n = 125) and 87 +/- 22 for women (n = 145). Mean daily protein intake was 83 g for men and 67 g for women and only 11% of men and 14% of women failed to receive at least 100% of the RDA for protein. Frequency and amount of vitamin and mineral supplementation was substantial. Approximately 60% of both men and women ingested one or more supplements; vitamins C and E were the most popular. In general, dietary intakes in this population appear to be adequate with the possible exception of vitamin D and calcium intakes in women.

Aged↗
PubMed1982

Nutritional status in a healthy elderly population: vitamin C.

Vitamin C status in 270 free-living and healthy elderly was determined from dietary intakes and plasma levels of ascorbic acid. Mean dietary intake for women (n = 145) was 137 and 142 mg/day for men (n = 125). The median intake of supplemental ascorbic acid for women was 355 mg/day (n = 85) and 500 mg/day (n = 70) for men. The mean plasma ascorbic acid level for women was 1.30 mg/dl and was significantly higher than for men, 1.13 mg/dl. Less than 2% were at risk for developing clinical symptoms of hypovitaminosis C. It was estimated that intakes needed to maintain a plasma ascorbic acid level of 1.0 mg/dl would be 75 mg/day for women and 150 mg/day for men. Our data suggest that a different recommended dietary allowance for ascorbic acid should be considered for men and women.

Aged↗
PubMed1982

Nutritional status in a healthy elderly population: riboflavin.

Riboflavin status in 270 free-living and healthy elderly was determined from dietary intake (3-day food records) and erythrocyte glutathione reductase activity coefficients (EGR-AC). High EGR-ACs (greater than 1.35) indicate poor riboflavin nutriture. Mean dietary intakes of riboflavin were 1.86 +/- 0.64 (SD) for males and 1.58 +/- 0.69 mg/day for females. Approximately 45% of the population were taking some supplemental riboflavin and total riboflavin intakes ranged from 0.65 to 165 mg/day. The mean EGR-AC for those taking supplemental riboflavin was significantly lower than that of the nonsupplemented group (1.06 and 1.16, respectively). Only three subjects had EGR-ACs greater than 1.35. A significant correlation was found between total riboflavin intake and EGR-AC (r = 0.53). In a separate population of 667 volunteers between the ages of 20 and 87 yr, a significant decrease in mean EGR-AC with age was found. The mean EGR-AC for those over 60 yr and not taking a supplement was 1.16 +/ 0.10 compared to 1.23 +/- 0.11 for those from 20 to 29 yr old. Inadequate riboflavin nutriture appears to be more of a problem for younger than older adults.

Age Factors↗
PubMed1982

Nutritional status in a healthy elderly population: vitamin D.

The vitamin D status in a group of healthy free-living elderly people was determined by measuring dietary and supplemental vitamin D intakes and the plasma concentration of 25-hydroxyvitamin D (25-OHD). Median dietary intake was 88 IU for Vitamin D, with 26% of the population taking a median supplement of 400 IU. Plasma 25-OHD was significantly lower in the elderly (15.5 ng/ml) compared to a younger control (29.1 ng/ml) population. Within the elderly population, the plasma 25-OHD demonstrated a seasonal influence (nadir in January, zenith in September) and was consistently higher for men compared to women. People taking vitamin D supplements had higher plasma 25-OHD concentrations regardless of seasonal influence. Plasma alkaline phosphatase, an index for bone loss, was inversely related to the plasma 25-OHD concentration. Inadequate dietary vitamin D intake and inadequate sunlight exposure appeared to be contributory to the observed low vitamin D status. It is suggested that American elderly consider using a combination of moderate vitamin D supplementation and increased sunlight exposure in order to improve their vitamin D nutriture.

Aged↗