Estimated net acid excretion inversely correlates with urine pH in vegans, lacto-ovo vegetarians, and omnivores.

OBJECTIVE: Diet affects urine pH and acid-base balance. Both excess acid/alkaline ash (EAA) and estimated net acid excretion (NAE) calculations have been used to estimate the effects of diet on urine pH. This study's goal was to determine if free-living vegans, lacto-ovo vegetarians, and omnivores have increasingly acidic urine, and to assess the ability of EAA and estimated NAE calculations to predict urine pH. DESIGN: This study used a cross-sectional design. SETTING AND PARTICIPANTS: This study assessed urine samples of 10 vegan, 16 lacto-ovo vegetarian, and 16 healthy omnivorous women in the Boston metropolitan area. Six 3-day food records from each dietary group were analyzed for EAA content and estimated NAE, and correlations with measured urine pH were calculated. RESULTS: The mean (+/- SD) urine pH was 6.15 +/- 0.40 for vegans, 5.90 +/- 0.36 for lacto-ovo vegetarians, and 5.74 +/- 0.21 for omnivores (analysis of variance, P = .013). Calculated EAA values were not significantly different among the three groups, whereas mean estimated NAE values were significantly different: 17.3 +/- 14.5 mEq/day for vegans, 31.3 +/- 8.5 mEq/day for lacto-ovo vegetarians, and 42.6 +/- 13.2 mEq/day for omnivores (analysis of variance, P = .01). The average deattenuated correlation between urine pH and EAA was 0.333; this value was -0.768 for estimated NAE and urine pH, with a regression equation of pH = 6.33 - 0.014 NAE (P = .02, r = -0.54). CONCLUSIONS: Habitual diet and estimated NAE calculations indicate the probable ranking of urine pH by dietary groups, and may be used to determine the likely acid-base status of an individual; EAA calculations were not predictive of urine pH.

Nutrition Academic Award: nutrition education in graduate medical education.

The Nutrition Academic Award received by Tufts University School of Medicine strengthened our first-year Nutrition and Medicine course and clearly resulted in more nutrition in third-year clerkships and residency programs. Standardized patient cases in nutrition counseling for cardiovascular disease and weight loss were developed and incorporated into the clerkships and residency programs in internal medicine and family medicine. This was a value-added benefit that provided practice in initiating lifestyle changes and motivational skills, while expanding nutrition education. Eight standardized patient educators were trained in collaboration with physicians in internal and family medicine. Six slide shows on nutrition topics, 1-2 h each, were developed and included clinical cases, dietary analysis, and patient handouts. The Medicine Clerkship included 4 nutrition sessions and the standardized patient experience, whereas the Family Medicine Clerkship included 1 nutrition session and the standardized patient experience. Working with faculty in the Department of Family Medicine, we developed a nutrition mentoring program for the family medicine residents and used 3 nutrition messages that were a modification of the Dietary Approaches to Stop Hypertension (DASH) diet to teach diet evaluation, intervention strategies, feedback from nutrition referrals, and follow-up. Seven sessions on nutrition and chronic disease with cases were offered to the residents in family medicine, which concluded with a nutrition intervention session using standardized patient educators. This expanded nutrition program in internal and family medicine along with the standardized patient experience receives excellent ratings from physicians, residents, and medical students.

Differences in serum sex hormone and plasma lipid levels in Caucasian and African-American premenopausal women.

CONTEXT: Risk of coronary heart disease is higher in African-American than in Caucasian women. OBJECTIVE: The aim of this study was to evaluate the contribution of sex hormone levels, race, and measures of body fat to the variation in plasma lipid levels, a well-established risk factor for coronary heart disease. DESIGN: This was a cross-sectional study. SETTING: The study was conducted in the general community. STUDY PARTICIPANTS: Sixty Caucasian and 117 African-American premenopausal women participated. MAIN OUTCOME MEASURES: Body weight, body mass index (BMI), and waist to hip circumference ratio (WHR), as well as plasma lipid and serum sex hormone levels, were assessed. RESULTS: Relative to Caucasian women, African-American women had significantly higher mean BMI (23.92 +/- 3.87 vs. 26.99 +/- 5.87 kg/m2, respectively; P < 0.001), and WHR (0.733 +/- 0.052 vs. 0.757 +/- 0.068; P < 0.03). Also, plasma triglyceride (TG) levels were significantly lower in African-American women (81 +/- 61 vs. 55 +/- 24 mg/dl; P < 0.0001). Serum estrone sulfate (556 +/- 323 vs. 442 +/- 332 pg/ml, Caucasian vs. African-American; P < 0.001), estradiol (E2) (55.1 +/- 43.6 vs. 35.8 +/- 17.7 pg/ml; P < 0.0001), androstenedione (2.6 +/- 0.9 vs. 1.6 +/- 0.7 ng/ml; P < 0.0001), and testosterone (0.36 +/- 0.12 vs. 0.31 +/- 0.19 ng/ml; P < 0.002) levels were significantly lower in African-American women than in Caucasian women. After correction for the effects of age, BMI, and WHR, serum E2 levels were significantly and positively associated with plasma high-density lipoprotein cholesterol levels in all women, and serum estrone sulfate levels with plasma total cholesterol and TG levels in African-American women. CONCLUSIONS: Our results indicate that race is an important determinant of plasma TG and serum sex hormone levels, even after adjustment for differences in body size. A significant association between endogenous E2 and high-density lipoprotein cholesterol levels exists in premenopausal women, independent of their race.

Role of n-3 fatty acids in prevention of disease complications in patients with HIV.

Hypertriglyceridemia and insulin resistance have been seen in patients with HIV. Beneficial effects of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been reported for these conditions. One study of n-3 fatty acid supplementation in patients with HIV reported a decrease in serum triglyceride levels. These marine fatty acids appear to be working at a number of sites to achieve an improvement in lipid metabolism and insulin sensitivity. There is disagreement about the amount of n-3 fatty acids needed to achieve different effects and about the optimal ratio of dietary n-6 and n-3 fatty acids.

Effect of dietary intake and protease inhibitors on serum vitamin B12 levels in a cohort of human immunodeficiency virus-positive patients.

The dietary intake of micronutrients and serum micronutrient status have been topics of concern in relation to human immunodeficiency virus (HIV) progression. Most data, however, were collected prior to the introduction of protease inhibitors (PIs). We analyzed dietary intake and serum values of vitamin B(12), including the effect of PIs, in a cohort of persons with HIV infection. During intervals with no PI use, each 1 microg/day increase in B(12) intake was associated with a 1.06 pg/mL increase in serum B(12) levels. However, during intervals with PI use, each 1 microg/day increase in intake was associated with only a 0.12 increase in serum B(12) levels. Adequate serum B(12) levels (>350 pg/mL) cannot be assumed even in the presence of PIs, and dietary supplementation may not be adequate to significantly increase serum B(12) levels. Serum B(12) levels should be determined yearly in persons with HIV infection, regardless of whether they are receiving PI treatment.

Plasma lipid and lipoprotein levels during the follicular and luteal phases of the menstrual cycle.

Estrogen levels are higher during the luteal compared with the follicular phase of the menstrual cycle. It was hypothesized that the luteal compared with the follicular phase has a lipid and lipoprotein profile associated with decreased coronary heart disease (CHD) risk. This was tested using well-defined data from healthy, well-characterized premenopausal Caucasian women under very controlled metabolic conditions. The percent differences in lipid, lipoprotein, and sex hormone levels between the follicular and luteal phases were estimated using generalized estimating equations after adjusting for age, body mass index, calendar time, and season. The low-density lipoprotein cholesterol (LDL-C) level was 6.2% lower (P = 0.015), and the total cholesterol/high-density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratios were 5.1% (P = 0.0006) and 8.4% (P = 0.002) lower, respectively, during the luteal phase. Levels of estradiol and other estrogens were significantly higher (by>100% each; P < 0.0001 in all cases) in the luteal phase. These findings support the study hypothesis. Fluctuations in levels of LDL-C and the total cholesterol/HDL-C and LDL-C/HDL-C ratios between menstrual cycle phases need to be considered in the screening and medical monitoring of premenopausal women, especially those with borderline levels. Although small, such fluctuations may prove to be clinically significant in the long run. Studies involving premenopausal women need to more clearly define and validate menstrual cycle phase in the design and interpretation of study results.

High-fiber diet in HIV-positive men is associated with lower risk of developing fat deposition.

BACKGROUND: Lipodystrophy has been described with increasing frequency in patients infected with HIV. This study focused on the identification of dietary components that may predispose HIV-positive patients to the development of fat deposition. OBJECTIVE: We evaluated differences in past dietary intake between men with HIV who developed fat deposition and those who did not. DESIGN: This nested case-control study consisted of 47 cases and 47 controls from the Nutrition for Healthy Living cohort. Food records from 6 to 24 mo before development of fat deposition in cases were analyzed and compared with food records from controls by using t tests for normally distributed nutrients and Wilcoxon rank-sum tests for nutrients with skewed distributions. RESULTS: HIV-positive patients without fat deposition had greater overall energy intakes (kcal/kg; P = 0.03) and greater intakes of total protein (P = 0.01), total dietary fiber (P = 0.01), soluble dietary fiber (P = 0.01), insoluble dietary fiber (P = 0.03), and pectin (P = 0.02) than did HIV-positive patients with fat deposition. Those without fat deposition also tended to currently perform more resistance training (P = 0.05) and to not be current smokers (P = 0.05). CONCLUSION: Our results indicate that an overall high-quality diet, rich in fiber and adequate in energy and protein, may be beneficial in preventing the development of fat deposition in persons infected with HIV. The results of this study further emphasize that a healthy lifestyle, including exercise and avoidance of unhealthy behaviors such as smoking, may also be similarly beneficial.

Nutrient intake and body weight in a large HIV cohort that includes women and minorities.

OBJECTIVE: Evaluate the baseline nutrient intake of an HIV positive population that includes significant representation from women and minorities, and determine the relationship between state of disease and nutritional intake. DESIGN: Baseline data from a prospective study (Nutrition for Healthy Living). SUBJECTS: Individuals with HIV in the Boston and Rhode Island area (n = 516); 25% were women and 30% were minorities. METHODS: Nutrient intakes from 3-day food records, which included vitamin/mineral supplements, were estimated by gender and nonwhite vs white categories, after grouping by CD4 lymphocyte counts. STATISTICAL ANALYSES: Spearman correlation coefficients, Wilcoxon signed rank test, Wilcoxon rank sum test, chi2 test, and restricted cubic spline model were used for data analyses as indicated. RESULTS: Macronutrient but not micronutrient intake was statistically and inversely associated with decreasing CD4 cell counts. The median intake of micronutrients was higher in the study sample compared with the same age and gender group in NHANES III data; however, 25% to 35% of the women in our study sample had dietary intakes of less than 75% of the DRIs for vitamins A, C, E and B-6, and iron and zinc. White men had statistically higher values of all micronutrients compared with nonwhite men. Body mass index for men and women ranged from 23 to 25. CONCLUSIONS/APPLICATIONS: Median values for micronutrient intake from food plus vitamin/mineral supplements were adequate in the overall population studied, but a large percent of women and minorities had inadequate nutrient intakes and would benefit from dietary assessment and counseling.

Micronutrient concentrations and subclinical atherosclerosis in adults with HIV.

BACKGROUND: Extremes in micronutrient intakes are common in HIV-infected patients in developed countries and may affect the progression of atherosclerosis in this population. OBJECTIVE: We completed a cross-sectional study examining the association between serum micronutrient concentrations and surrogate markers of atherosclerosis in a cohort of HIV-infected adults. DESIGN: We measured serum selenium, zinc, vitamin A, and vitamin E concentrations as well as carotid intima-media thickness (c-IMT) and coronary artery calcium (CAC) in 298 Nutrition for Healthy Living participants. We assessed cardiovascular disease risk factors, c-IMT, and CAC for each micronutrient tertile by using a chi-square test for binary variables and analysis of variance for continuous variables. We performed multivariate regression of c-IMT and CAC with each micronutrient with adjustment for HIV-related and cardiovascular disease risk factors. RESULTS: In the multivariate analysis, the highest tertile of serum vitamin E concentration was associated with higher common and internal c-IMT and CAC scores (P < 0.05 for c-IMT and CAC). Participants with higher vitamin E concentrations were more likely to have detectable CAC (50% compared with 44% compared with 67% for tertiles 1, 2, and 3, respectively; P = 0.004) and common c-IMT >0.8 mm (5% compared with 4% compared with 17% for tertiles 1, 2, and 3, respectively; P = 0.002). Other than vitamin E, micronutrients had no association with markers of atherosclerosis. CONCLUSIONS: Our study showed that elevated serum vitamin E concentrations are associated with abnormal markers of atherosclerosis and may increase the risk of cardiovascular complications in HIV-infected adults.

Effect of a dietary intervention and n-3 fatty acid supplementation on measures of serum lipid and insulin sensitivity in persons with HIV.

BACKGROUND: Elevated serum triglyceride and low HDL-cholesterol concentrations have been reported in persons with HIV. OBJECTIVE: The effect of a dietary intervention plus n-3 (omega-3) fatty acid supplementation on serum triglycerides and markers of insulin sensitivity was investigated. DESIGN: Fifty-four persons with HIV and elevated serum triglycerides (>150 mg/dL) and/or abnormal Quantitative Insulin Sensitivity Check Index values (<0.35 but >0.30) were recruited for a dietary intervention in which total fat, type of fat, fiber, and glycemic load were controlled along with supplementation with n-3 fatty acids to achieve an intake of 6 g/d. The subjects were randomly assigned to an intervention or control group, and serum lipids, markers of insulin sensitivity, and serum phospholipid fatty acids were measured in both groups at baseline, 3 wk, and 13 wk. RESULTS: Triglycerides in the intervention group decreased from a median of 180 mg/dL (interquartile range: 141, 396) to 114 mg/dL (interquartile range: 84, 169) from baseline to 3 wk, whereas they remained stable in the control group (P = 0.003). Serum phospholipid fatty acids indicated a decrease in de novo lipogenesis and a decrease in arachidonic acid (% nmol; P

Metabolic syndrome and serum fatty acid patterns in serum phospholipids in hypertriglyceridemic persons with human immunodeficiency virus.

BACKGROUND: HIV infection and its treatment are associated with abnormal lipid profiles. High triglyceride concentrations and low HDL-cholesterol concentrations are the most common health abnormalities and raise concerns about an increased risk of cardiovascular disease. OBJECTIVE: We compared the fatty acid patterns of serum phospholipids between persons with HIV and non-HIV controls to determine whether there are differences that explain the elevated triglyceride concentrations, insulin resistance, and inflammation that are part of the metabolic syndrome in patients with HIV. DESIGN: Thirty-nine persons with HIV and elevated serum triglycerides (>150 mg/dL) and/or indicators of insulin resistance were recruited to examine fatty acid profiles in serum phospholipid fractions relative to those of 2 control groups without HIV (n = 31). RESULTS: Higher concentrations of 16:1 and 18:0 fatty acids in the phospholipid fraction indicated increased lipogenesis in the HIV patients and in the non-HIV controls at risk of the metabolic syndrome. However, the subjects with HIV had higher concentrations of both n-6 (omega-6) and n-3 fatty acids of higher elongation and desaturation levels, which indicated a greater promotion of these pathways in this population. The nanomolar percentage (%nmol) arachidonic acid was the same in all 3 groups. CONCLUSIONS: Persons with and without HIV, at risk of the metabolic syndrome, show indications of increased lipogenesis, more so in subjects with HIV taking medication. Higher proportions of distal elongation and desaturation fatty acid products were seen only in the phospholipids fatty acid fraction of the subjects with HIV.

Micronutrient levels and HIV disease status in HIV-infected patients on highly active antiretroviral therapy in the Nutrition for Healthy Living cohort.

BACKGROUND: Low serum micronutrient levels were common before widespread use of highly active antiretroviral therapy (HAART) and were associated with adverse outcomes. Few data are available on micronutrient levels in subjects taking HAART. OBJECTIVE: To determine the prevalence of low serum retinol, alpha-tocopherol, zinc, and selenium in HIV-infected subjects taking HAART and to assess the association of micronutrient levels with HIV disease status. DESIGN: Cross-sectional. SETTING: Nutrition for Healthy Living (NFHL) study. PARTICIPANTS: HIV-infected subjects on HAART. METHODS: Retinol, alpha-tocopherol, zinc, and selenium were determined in frozen serum samples from 171 men and 117 women. Low serum levels were defined as retinol <30 microg/dL, selenium <85 microg/L, alpha-tocopherol <500 microg/dL, and zinc <670 microg/L. Association of micronutrient quartiles with CD4 cell count, CD4 count <200 cells/mm, HIV viral load (VL), and undetectable VL was assessed using adjusted multivariate regression. RESULTS: Five percent of men and 14% of women had low retinol, 8% of men and 3% of women had low selenium, and 7% of men and no women had low alpha-tocopherol. Forty percent of men and 36% of women had low zinc, however. Subjects in the upper quartiles of zinc had lower log VL levels than those in the lowest quartile (significant for women). Subjects in the upper quartiles of selenium also tended to have lower VL levels compared with those in the lowest quartile. Surprisingly, women in the upper quartiles of retinol had higher log VLs than those in the lowest quartile. There was no significant association of any micronutrient with CD4 cell count or likelihood of CD4 count <200 cells/mm. The level of CD4 cell count influenced the association of retinol with log VL in men, however. In men with CD4 counts >350 cells/mm, those with higher retinol had higher log VLs compared with the lowest quartile, whereas in men with CD4 counts <350, those with higher retinol levels had lower log VLs compared with the lowest quartile. CONCLUSIONS: Low retinol, alpha-tocopherol, and selenium are uncommon in HIV-infected subjects on HAART. Zinc deficiency remains common, however. Decreased retinol levels in women and in men with CD4 counts >350 cells/mm and increased zinc and selenium levels in both genders may be associated with improved virologic control.