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Biomedical subjects

P F Jacques

Publications and source records attributed to P F Jacques.

At least 73 records · Page 4Linked to original sources
PubMed1996

Use of albumin as a predictor of mortality in community dwelling and institutionalized elderly populations.

This study was undertaken to identify variables that could explain the association between low albumin and a 9- to 12-year mortality follow-up among 287 community- dwelling and 176 institutionalized people aged 60 years and over. A wide array of nutrition assessment variables was simultaneously examined in this population to identify confounders of the association. The results show that the risk of mortality for subjects with albumin values of 40 g/liter and over was 0.46 of the risk for those with albumin values below 40 g/liter, after controlling for the confounders age, blood urea nitrogen, triglyceride, history of diseases, and inability to shop owing to medical conditions. Similarly, albumin was also inversely associated with mortality among institutionalized subjects even after controlling for the confounders age, sex, blood urea nitrogen, transferrin, and history of stroke. However, the association was no longer significant among the institutionalized population once the deaths that occurred within the first 3 years after study participation were eliminated. The results indicate that albumin is a long-term predictor of mortality among noninstitutionalized subjects and increased mortality is not only a result of age, history of chronic diseases, medication use, or protein intake. Among institutionalized subjects, albumin appeared to be a short-term predictor of mortality.

Aged↗
PubMed1996

Relationship between plasma homocysteine, vitamin status and extracranial carotid-artery stenosis in the Framingham Study population.

Recent studies demonstrated associations between occlusive vascular disease and hyperhomocysteinemia of both genetic and nutritional origin. In the present study we analyzed plasma samples from the 20th biannual examination of the Framingham Heart Study cohort to determine distribution of plasma homocysteine concentrations with emphasis on relationships to B vitamins and prevalence of carotid artery stenosis. Results showed that homocysteine exhibited strong inverse association with plasma folate and weaker associations with plasma vitamin B-12 and pyridoxal-5'-phosphate (PLP). Homocysteine was also inversely associated with intakes of folate and vitamin B-6, but not vitamin B-12. Prevalence of high homocysteine (>14 micromol/l) was 29.3% in this cohort, and inadequate plasma concentrations of one or more B vitamins appear to contribute to 67% of the cases of high homocysteine. Prevalence of stenosis > or = 25% was 43% in men and 34% in women with an odds ratio of 2.0 for individuals in the highest homocysteine quartile (> or = 14.4 micromol/l) compared with those in the lowest quartile (< or = 9.1 micromol/l), after adjustment for sex, age, high density lipoprotein cholesterol, systolic blood pressure and cigarette smoking (Ptrend < 0.001). Plasma concentrations of folate and pyridoxal-5'-phosphate and folate intake were inversely associated with extracranial carotid stenosis after adjustment for age, sex and other risk factors.

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PubMed1995

Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis.

BACKGROUND: Epidemiologic studies have identified hyperhomocysteinemia as a possible risk factor for atherosclerosis. We determined the risk of carotid-artery atherosclerosis in relation to both plasma homocysteine concentrations and nutritional determinants of hyperhomocysteinemia. METHODS: We performed a cross-sectional study of 1041 elderly subjects (418 men and 623 women; age range, 67 to 96 years) from the Framingham Heart Study. We examined the relation between the maximal degree of stenosis of the extracranial carotid arteries (as assessed by ultrasonography) and plasma homocysteine concentrations, as well as plasma concentrations and intakes of vitamins involved in homocysteine metabolism, including folate, vitamin B12, and vitamin B6. The subjects were classified into two categories according to the findings in the more diseased of the two carotid vessels: stenosis of 0 to 24 percent and stenosis of 25 to 100 percent. RESULTS: The prevalence of carotid stenosis of > or = 25 percent was 43 percent in the men and 34 percent in the women. The odds ratio for stenosis of > or = 25 percent was 2.0 (95 percent confidence interval, 1.4 to 2.9) for subjects with the highest plasma homocysteine concentrations (> or = 14.4 mumol per liter) as compared with those with the lowest concentrations (< or = 9.1 mumol per liter), after adjustment for sex, age, plasma high-density lipoprotein cholesterol concentration, systolic blood pressure, and smoking status (P < 0.001 for trend). Plasma concentrations of folate and pyridoxal-5'-phosphate (the coenzyme form of vitamin B6) and the level of folate intake were inversely associated with carotid-artery stenosis after adjustment for age, sex, and other risk factors. CONCLUSIONS: High plasma homocysteine concentrations and low concentrations of folate and vitamin B6, through their role in homocysteine metabolism, are associated with an increased risk of extracranial carotid-artery stenosis in the elderly.

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PubMed1995

Post-methionine load hyperhomocysteinemia in persons with normal fasting total plasma homocysteine: initial results from the NHLBI Family Heart Study.

Hyperhomocysteimia, either fasting or after oral methionine loading, appears to be an independent risk factor for coronary heart disease (CHD). It remains unclear whether fasting total homocysteine determination alone adequately detects the full spectrum of hyperhomocysteinemic individuals. We measured fasting and 4-h post methionine loading (0.1 g L-methionine/kg body weight) total plasma homocysteine in 274 participants in The NHLBI Family Heart Study, a population-based investigation of genetic and non-genetic determinants of CHD. Of the total number (n = 47) of hyperhomocysteinemic persons, 43% (20/47) were identified only by methionine loading, while 32% (15/47) of the total number, and 75% of those with post-methionine loading hyperhomocysteinemia only (15/20), had fasting total homocysteine concentrations below the 75th percentile (10.7 mumol/l). We conclude that fasting total plasma homocysteine determination alone fails to identify a sizable percentage (> 40%) of persons who may have clinically relevant hyperhomocysteinemia post methionine loading.

Adult↗
PubMed1995

Effect of vitamin C supplementation on lipoprotein cholesterol, apolipoprotein, and triglyceride concentrations.

Plasma ascorbic acid (AA) frequently is positively correlated with high-density-lipoprotein (HDL) cholesterol and inversely related to total cholesterol concentration. To determine if vitamin C intake can alter cholesterol concentration, we examined the effect of vitamin C supplementation (1 g/d) on lipoprotein cholesterol and triglyceride levels in 138 subjects, aged 20 to 65 years, who completed an 8-month randomized, double-blinded, placebo-controlled trial. Individuals with higher levels of plasma AA (> 80 mumol/L for men and > 90 mumol/L for women), HDL cholesterol (> 1.4 mmol/L for men and > 1.7 mmol/L for women), and total cholesterol (> 6.7 mmol/L) were excluded from this trial. We observed no overall effect of supplementation on plasma concentrations of HDL, LDL, or total cholesterol, apolipoprotein (apo) B, or triglyceride. We did observe a marginally significant (P < 0.10) increase of 1.9 mumol/L (5.3 mg/dL) in apo A-I concentration with supplementation and a significant (P < 0.05) difference of 0.10 mmol/L (3.8 mg/dL) in HDL cholesterol concentration between vitamin C and placebo treatment in a nonrandomized subgroup of individuals (n = 43) and a baseline plasma AA level less than 55 mumol/L. Although the apo A-I concentration increase was only marginally significant with supplementation, change in plasma AA concentration was significantly (P < 0.05) correlated with change in apo A-I concentration in the entire sample. The overall results of this trial were negative, but our data do not allow us to rule out the possibility that vitamin C supplementation might increase HDL cholesterol or apo A-I concentrations among individuals with lower plasma AA levels.

Adult↗
PubMed1995

Influence of combined antioxidant nutrient intakes on their plasma concentrations in an elderly population.

Data from a cross-sectional survey of 746 non-institutionalized, Boston-area elderly individuals (aged > or = 60 y) were analyzed to assess the relation between antioxidant nutrient intake and plasma antioxidant status. Intakes of vitamin C and carotenoids and supplemental vitamin E were estimated by using 3-d diet records. Mean plasma concentrations of these nutrients were calculated within categories of intake, and polynomial contrasts were used to test for linear trends of the plasma nutrient concentrations across these categories. Adjustments for the corresponding intake of the plasma nutrient under consideration, as well as age, sex, and smoking status were made to minimize potential confounding. Plasma alpha-tocopherol concentrations were 18% greater in individuals consuming > or = 220 mg vitamin C/d compared with those with intakes < 120 mg/d (P for trend < 0.001). Plasma carotenoid concentrations were 13% higher across increasing categories of vitamin C intake (P for trend = 0.002). An increasing intake of carotenoids was moderately associated with higher plasma alpha-tocopherol (P for trend = 0.008) and unrelated to ascorbic acid status. An increasing intake of supplemental vitamin E was weakly correlated with plasma ascorbic acid (P for trend = 0.05) and unrelated to carotenoid status. These results provide epidemiologic evidence that increasing intake of either vitamin C, vitamin E, or carotenoids is associated with greater plasma concentrations of one or both of the other antioxidant vitamins and not associated with any impairment in antioxidant status.

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PubMed1995

Relations among aging, antioxidant status, and cataract.

Light and oxygen are necessary for the function of the eye. However, when present in excess or in uncontrolled circumstances, they appear to be related, probably causally, to the development of cataract. Compromises of function of the lens and retina with aging are exacerbated by depleted or diminished primary antioxidant reserves, antioxidant enzyme capabilities, and diminished secondary defenses such as proteases. Smoking appears to provide an additional oxidative challenge associated with depletion of antioxidants as well as with enhanced risk for cataract formation. Poor education and lower socioeconomic status are associated with poorer nutriture and are also significantly related to increased risk for these debilities. Optimizing nutriture, including diets rich in fruit and vegetables, may provide the least costly and most practicable means to delay cataract.

Aging↗
PubMed1994

High dose ascorbate supplementation fails to affect plasma homocyst(e)ine levels in patients with coronary heart disease.

Pharmacologic doses of folate, in the absence of clinical folate deficiency, can reduce plasma levels of the putatively atherothrombotic amino acid, homocysteine (H(e)). Data suggesting that H(e) may accumulate in experimental scurvy prompted us to explore the efficacy of high dose ascorbate supplementation as a H(e)-lowering treatment, in the absence of clinical ascorbate deficiency. A randomized, placebo-controlled trial of 12 weeks of high dose (4.5 g/day) ascorbate supplementation was completed by 44 patients with established coronary heart disease. No significant change in mean fasting total plasma H(e) levels was demonstrable despite a marked increase in mean fasting plasma ascorbate levels amongst those patients randomized to active treatment. Ascorbate supplementation to prevent the development of fasting hyperhomocysteinemia may only be relevant at scorbutic levels of plasma ascorbate.

Ascorbic Acid↗
PubMed1994

Effects of dietary intakes on plasma lipids, lipoproteins, and apolipoproteins in free-living elderly men and women.

Plasma lipid and apolipoprotein (apo) A-I and B concentrations and habitual dietary intakes were determined in 306 free-living elderly individuals (119 men and 187 women, age range 60-100 y). Plasma lipid and apo A-I concentrations were significantly higher in women than in men. In older men, plasma triglyceride, total cholesterol, and apo B concentrations were significantly lower than in younger men, whereas a significant trend towards lower LDL-cholesterol concentrations was observed in older women. Energy intake and percent macronutrient intake were not influenced by age. Higher carbohydrate intake was associated with lower HDL cholesterol and apo A-I concentrations, whereas higher total fat intake was associated with higher apo A-I concentrations. Higher vitamin A intake was associated with higher plasma concentrations of HDL cholesterol and apo A-I. Our data indicate that both dietary and plasma concentrations of vitamin A, body mass index, age, and sex are important determinants of plasma lipid concentrations in the elderly.

Aged↗
PubMed1994

Ascorbic acid and plasma lipids.

We examined the association between plasma lipids and total ascorbic acid in 256 men and 221 women age 20-65 years. Among men, we observed that high-density lipoprotein (HDL) cholesterol was 2.1 mg per dl higher, total:HDL cholesterol was 5.4% lower, total cholesterol was 4.8 mg per dl lower, low-density lipoprotein (LDL) cholesterol was 5.6 mg per dl lower, and triglyceride was 5.2% lower for each 0.5 mg per dl increment in ascorbic acid. The association between ascorbic acid and total:HDL cholesterol ratio in men was modified by glucose concentration. Among women, we observed that HDL cholesterol was 14.9 mg per dl higher for women with ascorbic acid levels < or = 1.05 mg per dl and 0.9 mg per dl lower for women with ascorbic acid levels > 1.05 mg per dl for each 0.5 mg per dl increment in ascorbic acid. Total:HDL cholesterol ratio was 10.9% lower for women with ascorbic acid concentrations < or = 1.45 mg per dl and 0.6% higher for women with ascorbic acid concentrations > 1.45 mg per dl for each 0.5 mg per dl increment. The associations among ascorbic acid concentration, total and LDL cholesterol, and triglyceride concentrations were weak or absent among women. These results are consistent with earlier observations relating ascorbic acid and HDL cholesterol and indicate that ascorbic acid might also be related to total and LDL cholesterol concentrations in men.

Adult↗
PubMed1993

Vitamin status and intake as primary determinants of homocysteinemia in an elderly population.

OBJECTIVE: To describe the distribution of plasma homocysteine concentrations in an elderly population and to analyze the relationship between homocysteine level and intake of vitamins and serum levels of vitamins that serve as coenzymes in homocysteine metabolism. DESIGN: Cross-sectional analysis of homocysteine levels and vitamin blood levels and intake in elderly participants in the Framingham Study. SETTING: Population-based cohort in Framingham, Mass. PARTICIPANTS: A total of 1160 adult survivors, aged 67 to 96 years, from the original Framingham Heart Study cohort. MAIN OUTCOME MEASURES: Plasma homocysteine concentration correlated with plasma folate, vitamin B12, pyridoxal-5'-phosphate (PLP), and oral intakes of these vitamins, and the contribution of these vitamins to the prevalence of elevated homocysteine in the population. RESULTS: Homocysteine levels were positively correlated with age after controlling for vitamin concentrations. After controlling for age, sex, and levels of other vitamins, homocysteine exhibited a strong inverse association with plasma folate. When subjects were grouped by deciles of plasma folate, mean homocysteine was significantly higher in the lowest two folate deciles (15.6 and 13.7 mumol/L, respectively) than in the highest decile (11.0 mumol/L). Homocysteine demonstrated weaker, inverse associations with plasma vitamin B12 and PLP. Similar inverse associations were demonstrated between homocysteine and intakes of folate and vitamin B6, but not vitamin B12. Prevalence of high homocysteine (> 14 mumol/L) was 29.3% in this cohort, and was greatest among subjects with low folate status. Inadequate plasma concentrations of one or more B vitamins appear to contribute to 67% of the cases of high homocysteine. CONCLUSIONS: These results indicate a strong association between homocysteine concentration and folate, vitamin B12, and vitamin B6 status, as well as age. It is possible that a substantial majority of the cases of high homocysteine in this older population can be attributed to vitamin status.

Aged↗
PubMed1993

Nutritional and economic advantages for homeless families in shelters providing kitchen facilities and food.

Food habits were examined in homeless families in Boston-area hotels and family shelters. Reported household income, food expenditures, food sources, and attitudes were analyzed for 77 caretakers grouped according to kitchen facilities provided and amount of food provided. Diets were analyzed using a 4-week semiquantitative food frequency questionnaire for 71 female respondents grouped by type of residence (hotel or shelter). Median monthly income was $589 and was similar among groups. Mean monthly food expenditures were lower for those who lived in shelters that provided standard kitchen facilities and substantial food support compared with those who lived in hotels without these amenities ($93 vs $244; P < .05). Compared with others, respondents who lived in hotels reported purchasing food more frequently (P < .05), were more likely to use food pantries (P < .01), and had fewer food items on hand (P < .01). They were less likely to be satisfied with their diets, access to food, and cooking and food storage facilities (P < .05). Nutrient intakes were frequently below two thirds of the Recommended Dietary Allowance for vitamin B-6 (63% of respondents), calcium (44%), and iron (44%). Vitamin A intakes were lower in hotel residents, as were vitamin B-6, vitamin C, and zinc per 1,000 kcal (P < .05). We conclude that services provided to homeless families in shelters and hotels may influence food expenditures, food procurement, and women's diets. Nutrition professionals should consider the availability of kitchen facilities and food when counseling homeless families.

Adult↗
PubMed1993

Comparison of micronutrient intake measured by a dietary questionnaire and biochemical indicators of micronutrient status.

We compared the intake of 12 micronutrients as reported on a semiquantitative food frequency questionnaire with corresponding biochemical indicators of nutrient status in a sample of 57 males and 82 females aged 40-83 y. Age-, sex-and energy-adjusted correlation coefficients ranged from near zero for thiamin, vitamin A, and zinc to 0.63 for folate. Correlation coefficients between intake and the biochemical measures were > 0.30 for carotenoids, vitamin D, vitamin E, vitamin B-12, folate, and vitamin C. Differences of 50% or more were observed between extreme quartiles of intake for mean plasma concentrations of folate, vitamin B-12, and vitamin C. Excluding nutrient supplement users generally reduced the correlations. These data demonstrate that food frequency questionnaires can provide valid information on intake for a number of micronutrients.

Adult↗
PubMed1992

Long-term morbidity and mortality of overweight adolescents. A follow-up of the Harvard Growth Study of 1922 to 1935.

BACKGROUND: Overweight in adults is associated with increased morbidity and mortality. In contrast, the long-term effect of overweight in adolescence on morbidity and mortality is not known. METHODS: We studied the relation between overweight and morbidity and mortality in 508 lean or overweight adolescents 13 to 18 years old who participated in the Harvard Growth Study of 1922 to 1935. Overweight adolescents were defined as those with a body-mass index that on two occasions was greater than the 75th percentile in subjects of the same age and sex in a large national survey. Lean adolescents were defined as those with a body-mass index between the 25th and 50th percentiles. Subjects who were still alive were interviewed in 1988 to obtain information about their medical history, weight, functional capacity, and other risk factors. For those who had died, information on the cause of death was obtained from death certificates. RESULTS: Overweight in adolescent subjects was associated with an increased risk of mortality from all causes and disease-specific mortality among men, but not among women. The relative risks among men were 1.8 (95 percent confidence interval, 1.2 to 2.7; P = 0.004) for mortality from all causes and 2.3 (95 percent confidence interval, 1.4 to 4.1; P = 0.002) for mortality from coronary heart disease. The risk of morbidity from coronary heart disease and atherosclerosis was increased among men and women who had been overweight in adolescence. The risk of colorectal cancer and gout was increased among men and the risk of arthritis was increased among women who had been overweight in adolescence. Overweight in adolescence was a more powerful predictor of these risks than overweight in adulthood. CONCLUSIONS: Overweight in adolescence predicted a broad range of adverse health effects that were independent of adult weight after 55 years of follow-up.

Activities of Daily Living↗
PubMed1992

A cross-sectional study of vitamin C intake and blood pressure in the elderly.

Data collected as part of a study designed to examine the nutritional status of non-institutionalized elderly individuals, ages 60-100 years, residing in the Boston area were used to investigate the relationship between blood pressure (BP) and vitamin C intake reported by three-day diet records. Four hundred and ten subjects not taking antihypertensive medications were grouped into 5 categories of vitamin C intake: < 60, 60-119, 120-179, 180-239, > or = 240 mg/day. Relative differences in systolic and diastolic BP between subjects consuming > or = 240 mg/day compared to those consuming < 60 mg/day were -6.9% (p < 0.05) and -6.6% (p < 0.05), respectively. The prevalence of elevated BP (systolic > or = 160 mmHg or diastolic > or = 100 mmHg) was approximately 50% lower (p < 0.05) across this range of vitamin C intake. Adjustment of these associations for age, sex, body mass, smoking, dietary sodium:potassium ratio, and other dietary factors did little to alter the relationship between vitamin C and BP. These results lend support to the hypothesis that vitamin C and BP are related, but further research is required to test whether the relationship is causal.

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