Genetic control of renal thiazide receptor response to dietary NaCl and hypertension.
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Excess NaCl increases blood pressure in some strains of animals but not others. An 8% NaCl diet did not change renal thiazide receptor (TZR) density in two salt-resistant normotensive rat strains (Wistar-Kyoto and Sprague-Dawley) [Fanestil, D. D., D. A. Vaughn, and P. Blakely. Am. J. Physiol. 273 (Regulatory Integrative Comp. Physiol. 42): R1241-R1245, 1997]. However, the renal response to salt differs in normal and hypertensive kidneys [Rettig, R., N. Bandelow, O. Patschan, B. Kuttler, B. Frey, and A. Uber. J. Hum. Hypertens. 10: 641-644, 1996]. Therefore, we examined two strains with salt-aggravated hypertension. Renal TZR did not change when Dahl-S (salt sensitive) animals became hypertensive with 8% dietary NaCl. In contrast, renal TZR decreased 34%, whereas blood pressure increased further, in SHR with 8% dietary NaCl. Blood pressure increased after NG-nitro-L-arginine in SHR, but renal TZR did not change, indicating the salt-induced decrease in TZR in SHR cannot be attributed nonspecifically to elevated arterial pressure. We conclude that the renal response to NaCl-induced increases in blood pressure can be genetically modulated independently of the genes that mediate either the primary hypertension or the salt sensitivity of the hypertension. This finding may be of use in future studies directed at identifying genotypes associated with salt-dependent hypertension. (+info)
Quality of life and performance in advanced head and neck cancer patients on concomitant chemoradiotherapy: a prospective examination.
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PURPOSE: To prospectively evaluate performance and quality of life (QOL) in advanced-stage head and neck cancer (HNC) patients on a curative-intent, concomitant-chemoradiotherapy (CT/XRT) (twice-daily radiation, fluorouracil, hydroxyurea, and cisplatin) regimen aimed at improving locoregional control, survival, and QOL. PATIENTS AND METHODS: Sixty-four patients were assessed before, during, and at 3-month intervals after treatment. Standardized measures of QOL (Functional Assessment of Cancer Therapy-Head and Neck), performance (Performance Status Scale for Head and Neck Cancer Patients and Karnofsky Performance Status Rating Scale), and patient-reported symptoms (McMaster University Head and Neck Radiotherapy Questionnaire) were administered. RESULTS: Acute treatment toxicities were severe, with declines in virtually all QOL and functional domains. Marked improvement was seen by 12 months; general functional and physical measures returned to baseline levels of good to excellent. Although up to a third of the patients continued to report problems with swallowing, hoarseness, and mouth pain, these difficulties were present in similar magnitudes before treatment. The following symptoms were more frequent at 12 months: dry mouth (58% v 17%), difficulties tasting (32% v 8%), and soft food diet (82% v 42%). Twelve-month diet was not related to pretreatment functioning, disease, treatment, or patient characteristics. Twelve-month QOL was best predicted by pretreatment QOL, with very little relationship to residual side effects or functional impairments. Small numbers of patients in four of the five disease sites precluded examination of outcome by site. CONCLUSION: These data support the feasibility of intense CT/XRT as primary treatment for advanced HNC. Results confirm acute toxicity but indicate that many of the treatment-related performance and QOL declines resolve by 12 months. The persistent inability to eat a full range of foods warrants further attention and monitoring. (+info)
Validity and reproducibility of a quantitative food frequency questionnaire for a cohort study in Japan.
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BACKGROUND: A self-administered quantitative food frequency questionnaire (Qx) was developed for a population-based cohort study on cancer in Takayama, Japan. METHODS: The Qx was tested among 58 male and 59 female volunteers. Average daily nutrient intakes for the previous year calculated from the Qx were compared with those from 3-day food records and four 24-h recalls. The Qx was also validated among 37 volunteers by comparing the nutrient intakes calculated from the Qx with 12 1-day food records during a year. We also calculated the intra-class correlation coefficients for various nutrients between the Qx and the second Qx administered by the same volunteers 1 year after the first survey. RESULTS: Pearson correlation coefficients between total energy from the Qx and 3-day records were 0.38 for men and 0.25 for women and those between the Qx and 24-h recalls were 0.19 and -0.02 for men and women, respectively. Correlations between the several nutrients from the Qx and 3-day records ranged from 0.2 to 0.5 for both men and women. These correlations after energy adjustment ranged from 0.2 to 0.6 for men and from 0.1 to 0.7 for women. In general, the correlations for various nutrients between the Qx and 12 1-day records were higher than those described above. The intra-class correlation coefficients ranged from 0.46 to 0.78 in men and from 0.36 to 0.67, except for vitamin C in women. When the information on portion size was excluded, almost all of the above indices showed somewhat lower figures. CONCLUSION: These results suggest that our food frequency questionnaire with portion size information can be used to estimate nutrient intakes of each individual. (+info)
Dietary magnesium, not calcium, regulates renal thiazide receptor.
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This study reports for the first time a relationship between dietary Mg and the renal thiazide-sensitive Na-Cl cotransporter (TZR, measured by saturation binding with 3H-metolazone). Ion-selective electrodes measured plasma ionized magnesium (PMg++), calcium (PCa++), and potassium (PK+). Restricting dietary Mg for 1 wk decreased PMg++ 18%, TZR 25%, and renal excretion of magnesium (UMg) and calcium (UCa) more than 50% without changing PCa++, PK+, or plasma aldosterone. A low Mg diet for 1 d significantly decreased PMg++, TZR, UMg and UCa. Return of dietary Mg after 5 d of Mg restriction restored PMg++ and TZR toward normal. In the control, Mg-deficient, and Mg-repleting animals, TZR correlated with PMg++ (r = 0.86) and with UMg (r = 0.87) but not UCa (r = 0.09). Increasing oral intake of Mg for 1 wk increased PMg++ 14%, TZR 32%, UMg 74%, and UCa more than fourfold without changing PCa++ or PK+. In contrast, increasing dietary Ca content from 0.02% to 1.91% did not change TZR, but increased UCa fivefold without changing PCa++. Hormonal mediators (if any) involved in the relationship between dietary Mg and TZR remain to be elucidated, as does the relationship between TZR and tubular reabsorption of Mg. (+info)
Dietary variety within food groups: association with energy intake and body fatness in men and women.
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BACKGROUND: Short-term experimental studies suggest that dietary variety may influence body fatness but no long-term human studies have been reported. OBJECTIVE: The purpose of this study was to determine whether dietary variety within food groups influences energy intake and body fatness. DESIGN: Seventy-one healthy men and women (aged 20-80 y), who provided accurate reports of dietary intake and completed a body-composition assessment, were studied. RESULTS: Dietary variety was positively associated with energy intake within each of 10 food groups (r = 0.27-0.56, P < 0.05). In multiple regression analysis with age and sex controlled for, dietary variety of sweets, snacks, condiments, entrees, and carbohydrates (as a group) was positively associated with body fatness (partial r = 0.38, P = 0.001) whereas variety from vegetables was negatively associated (partial r = -0.31, P = 0.01) (R2 = 0.46, P < 0.0001). In separate models, both a variety ratio (variety of vegetables/variety of sweets, snacks, condiments, entrees, and carbohydrates) and percentage dietary fat were significant predictors of body fatness (controlled for age and sex, partial r = -0.39 and 0.31, respectively, P < 0.01). However, dietary fat was no longer significantly associated with body fatness when the variety ratio and dietary fat were included in the same model. CONCLUSIONS: Our data, coupled with those of previous short-term studies, suggest that a high variety of sweets, snacks, condiments, entrees, and carbohydrates coupled with a low variety of vegetables promotes long-term increases in energy intake and body fatness. These findings may help explain the rising prevalence of obesity. (+info)
Serum and red blood cell folate concentrations, race, and education: findings from the third National Health and Nutrition Examination Survey.
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BACKGROUND: Little is known about the relations between race or ethnicity, educational attainment, and serum and red blood cell folate concentrations. OBJECTIVE: We examined the relation between educational attainment and serum and red blood cell folate concentrations in 8457 white, African American, and Mexican American men and women aged > or = 17 y. DESIGN: We performed a cross-sectional analysis using data from Phase 1 of the third National health and Nutrition Examination Survey (1988-1991). RESULTS: White men had significantly higher adjusted serum and red blood cell folate concentrations (16.9 and 502.6 nmol/L, respectively) than did African American men (15.6 and 423.3 nmol/L, respectively) or Mexican American men (16.0 and 457.0 nmol/L, respectively); white women had significantly higher concentrations (18.4 and 515.9 nmol/L, respectively) than did African American women (16.3 and 415.4 nmol/L, respectively) or Mexican American women (15.9 and 455.7 nmol/L, respectively). For the entire sample, rank correlation coefficients between educational attainment and serum and red blood cell folate were 0.11 and 0.12, respectively, and were larger in white participants than in other participants. No significant linear trends between adjusted serum or red blood cell folate and educational attainment were found. Among participants with > 12 y of education, the mean adjusted concentrations of serum folate were 15% and 18% lower and those of red blood cell were 18% and 22% lower in African American men and women than in white men and women, respectively. CONCLUSIONS: African Americans and Mexican Americans could benefit most from public health programs to boost folate intakes by encouraging increased intake of folate-rich foods and vitamin supplements. (+info)
Influence of dietary fat on the nutrient intake and growth of children from 1 to 5 y of age: the Special Turku Coronary Risk Factor Intervention Project.
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BACKGROUND: Excessive decreases in fat intake in young children have been linked with low intakes of energy and nutrients and possible growth failure. OBJECTIVE: We evaluated nutrient intakes and growth of healthy children with different fat intakes during the first 5 y of life. DESIGN: In the Special Turku Coronary Risk Factor Intervention Project (STRIP), 7-mo-old children were randomly assigned to an intervention aimed at reduced consumption of saturated fat and cholesterol (n = 540) or to a control group (n = 522). This analysis comprises data for children for whom > or = 6 of 8 possible 3-4-d food records were available (n = 730; 353 females). Children were divided according to fat intake pattern (percentage of energy) between the ages of 13 mo and 5 y into groups with continuously high fat intake (5% of children), increasing fat intake (5%), continuously low fat intake (5%), decreasing fat intake (5%), and average fat intake (80%). Children's energy and nutrient intakes and growth were then compared by analysis of variance. RESULTS: Fat intake at 13 mo of age was particularly low (21% of energy) in the increasing fat intake group and in the continuously low fat intake group (22% of energy at 13 mo; 26% of energy at 5 y). Growth of children in all 5 fat intake groups, however, was not significantly different throughout the study period. Intakes of vitamins and minerals, except of vitamin D, met recommended dietary allowances in all fat intake groups. CONCLUSION: Nutrient intakes and growth were not significantly different in children whose fat intake patterns differed between 13 mo and 5 y of age. (+info)
Age-related hearing loss, vitamin B-12, and folate in elderly women.
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BACKGROUND: Hearing impairment is 1 of the 4 most prevalent chronic conditions in the elderly. However, the biological basis of age-related hearing loss is unknown. OBJECTIVE: The objective was to test the hypothesis that age-related hearing loss may be associated with poor vitamin B-12 and folate status. DESIGN: A thorough audiometric assessment was conducted in 55 healthy women aged 60-71 y. Hearing function was determined by the average of pure-tone air conduction thresholds at 0.5, 1, 2, and 4 kHz and was categorized into 2 groups for logistic regression analyses: normal hearing (<20 dB hearing level; n = 44) and impaired hearing (> or = 20 dB hearing level; n = 11). RESULTS: Mean age was the same (65 y) for the normal hearing and impaired hearing groups. Pure-tone averages were inversely correlated with serum vitamin B-12 (r = -0.58, P = 0.0001) and red cell folate (r = -0.37, P = 0.01). Women with impaired hearing had 38% lower serum vitamin B-12 (236 compared with 380 pmol/L, respectively, P = 0.008) and 31% lower red cell folate (425 compared with 619 nmol/L, respectively, P = 0.02) than women with normal hearing. Among participants who did not take supplements containing vitamin B-12 or folate, women with impaired hearing had 48% lower serum vitamin B-12 (156 compared with 302 pmol/L, respectively, P = 0.0007) and 43% lower red cell folate (288 compared with 502 nmol/L, respectively, P = 0.001) than women with normal hearing. CONCLUSION: Poor vitamin B-12 and folate status may be associated with age-related auditory dysfunction. (+info)