Dietary calcium, dairy food intake and metabolic abnormalities in HIV-infected individuals

Dietary calcium intake in relation to blood lipids and lipoproteins profiles: A systematic review and meta-analysis of epidemiologic studies

AIMS

Findings of prior investigations on the association between calcium intake and lipid profiles were inconsistent. We performed a systematic review and meta-analysis on epidemiologic studies to evaluate the relationship of dietary calcium intake with blood lipids and lipoproteins.

DATA SYNTHESIS

A systematic search up to April 2021 was performed in different electronic databases, including MEDLINE (PubMed), Scopus, Web of Science (ISI), and Google Scholar for epidemiological studies that considered dietary calcium intake as the exposure and reported risk of dyslipidemia or blood lipids and lipoproteins concentrations (as mean ± SD or mean ± SE or median (Inter Quartile Range) as the outcomes of interest in adult populations from both genders (18 years or older), regardless of their health status. Nineteen cross-sectional studies were included in the analysis. Combining estimates from 11 studies (including 33,304 subjects) revealed that individuals in the highest category of calcium intake, compared to the lowest one, had 5.94 mg/dL lower circulating triglyceride (TG) concentration (weighted mean difference (WMD): -5.94; 95% CI: -8.27, -3.62), 4.02 mg/dL lower circulating low-density lipoprotein cholesterol (LDL-c) levels (WMD: -4.02; 95% CI: -7.08, -0.95), and 1.56 mg/dL higher blood high-density lipoprotein cholesterol (HDL-c) (WMD: 1.56; 95% CI: 0.81, 2.30). Although meta-analysis on 13 studies (including 38,714 participants) did not reveal a significant relationship between dietary calcium intake and odds of dyslipidemia or hyperlipidemia in the whole population, the highest vs. lowest level of calcium intake was related to 42% decreased odds of low blood HDL-c levels in females (95% CI: 0.40, 0.84) and 41% increased odds in males (95% CI: 1.21, 1.65).

CONCLUSIONS

This meta-analysis demonstrated that individuals with the highest dietary calcium intake might have lower blood TG, LDL-c, and higher HDL-c concentrations as compared to those with the lowest calcium intake. However, the linkage between dietary calcium intake with odds of hyperlipidemia or dyslipidemia was not significant. Because of the cross-sectional nature of included studies, causality could not be proven. Further prospective studies are needed to affirm these findings.

Long-term yogurt consumption and risk of incident hypertension in adults

OBJECTIVE

To evaluate the relation between yogurt consumption as well as cheese, milk, and total dairy, and high blood pressure (HBP) in two Nurses' Health Study cohorts (NHS, n = 69 298), NHS II (n = 84 368) and the Health Professionals Follow-Up Study (HPFS, n = 30 512).

METHODS

NHS, NHS II, and HPFS participants were followed for incident HBP for up to 30, 20, and 24 years, respectively. Hazard ratios were calculated using time-dependent multivariate-adjusted Cox proportional hazards models. Pooled risk estimates were derived from fixed effects meta-analyses.

RESULTS

Participants consuming at least five servings per week (vs. <1 serving per month) of yogurt in NHS, NHS II, and HPFS had 19% (95% CI 0.75-0.87), 17% (95% CI 0.77-0.90), and 6% (95% CI 0.83-1.07) lower HBP risks, respectively. In pooled analyses of these cohorts, higher yogurt consumption was linked with 16% (95% CI 0.80-0.88) lower HBP risk; higher total dairy (3 to <6 vs. <0.5 servings/day), milk (2 to <6/day vs. <4/week) and cheese (1 to 4/day vs. <1/week) were associated with 16% (95% CI 0.81-0.87), 12% (95% CI 0.86-0.90), and 6% (95% CI 0.90-0.97) lower HBP risks, respectively. After controlling for BMI as a possible causal intermediate, total dairy, yogurt, milk, and cheese were associated with 13, 10, 8, and 8% lower HBP risks, respectively. The combination of higher yogurt intake and higher DASH ('Dietary Approaches to Stop Hypertension') diet scores was associated with 30% (95% CI 0.66-0.75) lower HBP risk compared with lower levels of both factors.

CONCLUSION

Higher total dairy intake, especially in the form of yogurt, was associated with lower risk of incident HBP in middle-aged and older adult men and women.

A Meta-Analysis of the Metabolic Syndrome Prevalence in the Global HIV-Infected Population

BACKGROUND

Cardio-metabolic risk factors are of increasing concern in HIV-infected individuals, particularly with the advent of antiretroviral therapy (ART) and the subsequent rise in longevity. However, the prevalence of cardio-metabolic abnormalities in this population and the differential contribution, if any, of HIV specific factors to their distribution, are poorly understood. Therefore, we conducted a systematic review and meta-analysis to estimate the global prevalence of metabolic syndrome (MS) in HIV-infected populations, its variation by the different diagnostic criteria, severity of HIV infection, ART used and other major predictive characteristics.

METHODS

We performed a comprehensive search on major databases for original research articles published between 1998 and 2015. The pooled overall prevalence as well as by specific groups and subgroups were computed using random effects models.

RESULTS

A total of 65 studies across five continents comprising 55094 HIV-infected participants aged 17-73 years (median age 41 years) were included in the final meta-analysis. The overall prevalence of MS according to the following criteria were: ATPIII-2001:16.7% (95%CI: 14.6-18.8), IDF-2005: 18% (95%CI: 14.0-22.4), ATPIII-2004-2005: 24.6% (95%CI: 20.6-28.8), Modified ATPIII-2005: 27.9% (95%CI: 6.7-56.5), JIS-2009: 29.6% (95%CI: 22.9-36.8), and EGIR: 31.3% (95%CI: 26.8-36.0). By some MS criteria, the prevalence was significantly higher in women than in men (IDF-2005: 23.2% vs. 13.4, p = 0.030), in ART compared to non-ART users (ATPIII-2001: 18.4% vs. 11.8%, p = 0.001), and varied significantly by participant age, duration of HIV diagnosis, severity of infection, non-nucleoside reverse transcriptase inhibitors (NNRTIs) use and date of study publication. Across criteria, there were significant differences in MS prevalence by sub-groups such as in men, the Americas, older publications, regional studies, younger adults, smokers, ART-naïve participants, NNRTIs users, participants with shorter duration of diagnosed infection and across the spectrum of HIV severity. Substantial heterogeneities across and within criteria were not fully explained by major study characteristics, while evidence of publication bias was marginal.

CONCLUSIONS

The similar range of MS prevalence in the HIV-infected and general populations highlights the common drivers of this condition. Thus, cardio-metabolic assessments need to be routinely included in the holistic management of the HIV-infected individual. Management strategies recommended for MS in the general population will likely provide similar benefits in the HIV-infected.

Recommendations for evaluation and management of bone disease in HIV

Thirty-four human immunodeficiency virus (HIV) specialists from 16 countries contributed to this project, whose primary aim was to provide guidance on the screening, diagnosis, and monitoring of bone disease in HIV-infected patients. Four clinically important questions in bone disease management were identified, and recommendations, based on literature review and expert opinion, were agreed upon. Risk of fragility fracture should be assessed primarily using the Fracture Risk Assessment Tool (FRAX), without dual-energy X-ray absorptiometry (DXA), in all HIV-infected men aged 40-49 years and HIV-infected premenopausal women aged ≥40 years. DXA should be performed in men aged ≥50 years, postmenopausal women, patients with a history of fragility fracture, patients receiving chronic glucocorticoid treatment, and patients at high risk of falls. In resource-limited settings, FRAX without bone mineral density can be substituted for DXA. Guidelines for antiretroviral therapy should be followed; adjustment should avoid tenofovir disoproxil fumarate or boosted protease inhibitors in at-risk patients. Dietary and lifestyle management strategies for high-risk patients should be employed and antiosteoporosis treatment initiated.

Nutrition and the HIV-associated lipodystrophy syndrome

HIV-associated lipodystrophy syndrome (HALS), comprising metabolic and morphological alterations, is a known side effect of highly active antiretroviral therapy (HAART). Evidence for the role of nutrition in the management of the systemic parameters of HALS is currently limited. In the present paper we review the current knowledge base surrounding HALS, focusing particularly on the role of nutrition in mitigating the systemic parameters of the syndrome. Reported prevalence of HALS was found to vary from 9 to 83 % due to lack of a standardised definition, as well as variations in assessment methods and in the study population used. HALS is associated with both morphological (lipoatrophy, lipohypertrophy) and metabolic (dyslipidaemia, glucose intolerance, diabetes, hypertension, endothelial dysfunction and atherosclerosis) alterations, which may occur singly or in combination, and are associated with an increased risk of CVD. HAART-induced adipocyte inflammation, oxidative stress and macrophage infiltration, as well as altered adipocyte function and mitochondrial toxicity, have been shown to be central to the development of HALS. The adipocyte, therefore, represents a plausible target for treatment. Pharmacological and surgical treatment interventions have shown effect. However, their use is associated with numerous adverse effects and complications. Targeted lifestyle interventions may provide a useful alternative for managing HALS owing to their safety and tolerability. A Mediterranean-style diet has been found to be effective in improving the systemic parameters of HALS. Furthermore, the effects of n-3 PUFA supplementation are encouraging and future randomised controlled trials investigating the beneficial effects of n-3 PUFA in HALS are justified.

Dairy and blood pressure: a fresh look at the evidence

The Dietary Guidelines for Americans, 2010 indicated there is moderate evidence for an association between the consumption of dairy foods and lower blood pressure in adults; however, it also stated that more evidence was needed, especially in clinical trials, to fully delineate a causal relationship. The purpose of this review is to provide background by examining the historical literature and the evidence reviewed by the 2010 Dietary Guidelines Advisory Committee, to examine the gaps in knowledge indicated by that committee, and to determine if recently published evidence is sufficient to elucidate or dismiss an association between dairy foods and blood pressure maintenance. Examination of the newly published literature, together with evaluation of the evidence as a whole, shows that the preponderance of evidence indicates dairy foods are beneficially associated with blood pressure; however, additional research is necessary to identify the mechanism of action of dairy foods. New evidence should come from carefully designed clinical trials that examine not only blood pressure outcomes but also the ability of dairy foods to affect the vasculature.

Inadequate food intake among adults living with HIV

CONTEXT AND OBJECTIVE The number of people living with HIV (PLHIV) in Brazil is between 600,000 and 890,000. Assessing the diet is important in planning healthcare actions and improving PLHIV's quality of life. This study aimed to estimate the prevalence of inappropriate protein, total fat, saturated fat, carbohydrate, fiber, sodium, calcium and cholesterol intake among PVHIV on highly-active antiretroviral therapy (HAART). DESIGN AND SETTING Cross-sectional study in nine Specialized STD/AIDS Healthcare Centers in São Paulo. METHODS Men and women aged 20 to 59 years, on HAART for at least three months, were included. Nutrient intake was assessed using 24-hour food recall applied in person and repeated among 30% of the population by telephone. The between and within-person variances were corrected. RESULTS 507 individuals were evaluated: 58% male, mean age 41.7 years (standard deviation, SD = 7.8). The mean time since HIV diagnosis was 6.6 years (SD = 4.1), and since HAART onset, 5.1 years (SD = 3.3). More than 20% of the population presented intake above the recommendations for saturated fat, cholesterol and/or sodium, and below the recommendations for fiber. The recommended maximum tolerable sodium level was exceeded by 99% of the sample, and 86% of men and 94% of women did not reach the daily recommendations for calcium. Protein, carbohydrate and total fat intakes were adequate for the majority of the population. CONCLUSIONS A significant portion of the population presented inappropriate intake of saturated fat, sodium, fiber and calcium. Interventions aimed at improving PLHIV's dietary quality are needed.

Dairy calcium intake and lifestyle risk factors for bone loss in hiv-infected and uninfected Mediterranean subjects

BACKGROUND

Despite the reported high prevalence of osteoporosis in the human immunodeficiency virus (HIV)-population, there have been no previous studies examining dairy calcium intake and bone mineral density (BMD) in HIV-subjects. We assessed the prevalence of low BMD in HIV-infected and uninfected subjects and analyzed the effects of calcium intake, lifestyle and HIV-related risk factors on BMD.

METHODS

One hundred and twelve HIV-infected subjects were consecutively enrolled. Seventy- six HIV-uninfected subjects matched for age and sex were enrolled as the control group. The HIV-subjects were interviewed about lifestyle habits and completed a weekly food-frequency questionnaire to estimate calcium intake. HIV-RNA, CD4+ T-cell count and data on antiretroviral therapy were also recorded. Both biochemical bone turnover markers and BMD, assessed by dual-energy radiographic absorptiometry (DXA) were recorded in the HIV-cases and controls. We also calculated the 10-year fracture risks using the WHO FRAX equation.

RESULTS

Osteoporosis prevalence was significantly higher in the HIV-cases than controls (p < 0.05). BMI values were positively correlated with BMD (p < 0.05). Vitamin D levels were lower in the HIV-subjects (p < 0.02). No correlation was found with daily calcium intake. BMI values were significantly correlated with dairy intake quartiles (p < 0.003). In HIV-subjects, the mean of FRAX score was 1.2 % for hip and 4.7 % for major osteoporotic fractures. On multivariate analysis of the lumbar spine DXA T-score, age (p < 0.005) and HIV/hepatitis C virus co-infection (p < 0.0001) were negatively correlated with BMD, while yogurt intake was a protective predictor of BMD (p < 0.05). In the femur DXA T-score, age (p < 0.01), nadir CD4 + T-cell count < 200 cells/μL (p < 0.05) and drug addiction ( p < 0.0001) were negatively correlated with BMD.

CONCLUSIONS

Among the foods rich in calcium, yogurt was a protective predictor of BMD in HIV-subjects. HIV/HCV co-infection, nadir CD4 + T-cell count < 200 cells/μL and drug addiction were independent predictors of severe BMD. Promoting behavioral changes in food intake and lifestyle, aimed at the primary prevention of bone disease in the chronically-infected subjects seems to be essential for implementing medical intervention in these cases.

Calcium and vitamin D in obesity

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.