Effects of low-carbohydrate diets, with and without caloric restriction, on inflammatory markers in adults: a systematic review and meta-analysis of randomized clinical trials

Low-carbohydrate diets (LCDs) have gained interest due to their favorable effects on health outcomes, such as inflammation. However, further research is needed to ascertain the overall effects of LCDs on inflammatory parameters, but at the same time considering weight loss and calorie intake. Thus, a systematic review and meta-analysis of randomized clinical trials was performed to investigate the effects of LCDs compared with low-fat diets (LFDs), with and without caloric restriction, on inflammatory markers in adults. PubMed, Scopus, and Web of Science were searched through March 2022 to select intervention studies addressing LCDs vs. LFDs, in which the following circulating inflammatory markers were used: C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and interleukin (IL-6). Analyses were conducted comparing LCDs vs. LFDs through weighted mean differences (WMD) or standardized mean differences (SMD) and 95% confidence intervals (95% CIs) using random effects models. The systematic review and meta-analysis included a total of 51 studies with a total sample of 4,164 adults, with or without other chronic diseases. Intervention durations ranged from 2-144 weeks. LCDs, compared with LFDs, significantly decreased body weight [WMD = -1.35%, p = 0.001], CRP [SMD = -0.1, p = 0.03], and IL-6 [SMD = -0.15, p = 0.09]. However, LCDs did not significantly decrease TNF-α [SMD = -0.02, p = 0.7] compared to LFDs. In conclusion, LCDs have a beneficial effect on markers of inflammation by decreasing CRP and IL-6; this effect has an association with weight loss. However, LCDs were not more effective than LFDs in decreasing TNF-α.

Is breakfast consumption detrimental, unnecessary, or an opportunity for health promotion? A review of cardiometabolic outcomes and functional food choices

Breakfast consumption is generally considered a health-promoting habit for cardiometabolism, particularly with regard to chrononutrition. Glucose uptake is enhanced by proper insulin secretion triggered by the pancreatic clock, averting metabolic dysregulation related to insulin resistance. Breakfast skipping, in turn, is often considered a behaviour detrimental to health, in part due to putative inverse metabolic actions compared to breakfast consumption, such that breakfast skipping may promote circadian desynchrony. However, most ill health concerns about breakfast skipping are inferred from observational research, and recent well-controlled randomized clinical trials have shown benefits of breakfast skipping for cardiovascular risk factors. Accordingly, this review describes the effects of breakfast consumption versus breakfast skipping on cardiovascular risk factors (blood pressure and glycaemic and lipid indices). In addition, the view of breakfast consumption as an opportunity for functional food ingestion is considered to provide further insights into decision-making practice. Collectively, both breakfast consumption and breakfast skipping can be considered viable habits, but they depend on individual preferences, planning, and the specific foods being consumed or omitted. When consumed, breakfast should consist primarily of functional foods typical for this meal (e.g., eggs, dairy products, nuts, fruits, whole grains, coffee, tea, etc.). While breakfast consumption aligns with chrononutrition principles, breakfast skipping can contribute to a calorie deficit over time, which has the potential for widespread cardiometabolic benefits for patients with overweight/obesity. The concepts and practical considerations discussed in the present review may aid health care personnel in personalising breakfast consumption recommendations for diverse patient populations.

The effects of blueberry and cranberry supplementation on blood pressure in patients with cardiovascular diseases: A systematic review and meta-analysis of randomized clinical trials

Blueberries and cranberries are berry fruits with the highest number of randomized clinical trials (RCTs) focusing on blood pressure (BP). This systematic review and meta-analysis of RCTs analyzed the effects of blueberry and cranberry supplementation alone and in concert with systolic BP (SBP) and diastolic BP (DBP) in patients with cardiometabolic diseases. The searches were performed until August 2023 in the following databases: PubMed, Scopus, Web of Science, Cochrane, and Embase. Studies that examined the effects of blueberry or cranberry intake/supplementation were included. The risk of bias was evaluated using the Rob 2 scale. A meta-analysis was performed to estimate the effects of blueberry and cranberry supplementation on BP levels in patients with cardiometabolic diseases. A total of 17 articles were included, from which two found significant results from blueberry and/or cranberry supplementation in reducing BP. Pooled results revealed statistically non-significant reductions of -0.81 mm Hg for SBP (95% confidence interval [CI]: -2.26, 0.63; I2  = 0%) and -0.15 mm Hg for DBP (95% CI: -1.36, 1.05; I2  = 27%). Blueberry and/or cranberry supplementation had neutral effects on SBP and DBP in patients with cardiometabolic diseases, regardless of duration or age. Further high-quality studies are needed to firmly establish clinical efficacy.

Elevated neutrophil-lymphocyte ratio is associated with high rates of ICU mortality, length of stay, and invasive mechanical ventilation in critically ill patients with COVID-19 : NRL and severe COVID-19

Neutrophil and lymphocyte ratio (NLR) has emerged as a complementary marker in intensive care. This study aimed to associate high NLR values with mortality as the primary outcome, and length of stay and need for invasive mechanical ventilation as secondary outcomes, in critically ill patients with COVID-19. A cross-sectional study encompassing 189 critically ill patients with COVID-19 was performed. The receiver operating characteristic curve was used to identify the best NLR cutoff value for ICU mortality (≥ 10.6). An NLR ≥ 10.6, compared with an NLR < 10.6, was associated with higher odds of ICU mortality (odds ratio [OR], 2.77; 95% confidence interval [CI], 1.24-6.18), ICU length of stay ≥ 14 days (OR, 3.56; 95% CI, 1.01-12.5), and need for invasive mechanical ventilation (OR, 5.39; 95% CI, 1.96-14.81) in the fully adjusted model (age, sex, kidney dysfunction, diabetes, obesity, hypertension, deep vein thrombosis, antibiotics, anticoagulants, antivirals, corticoids, neuromuscular blockers, and vasoactive drugs). In conclusion, elevated NLR is associated with high rates of mortality, length of stay, and need for invasive mechanical ventilation in critically ill patients with COVID-19.

Effects of intermittent fasting regimens on glycemic, hepatic, anthropometric, and clinical markers in patients with non-alcoholic fatty liver disease: Systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Intermittent fasting (IF) regimens have been hypothesized to influence several markers of cardiometabolic and liver function. The objective of our meta-analysis was to investigate the impact of IF regimens on cardiometabolic and liver markers in subjects diagnosed with non-alcoholic fatty liver disease (NAFLD).

METHODS

We searched several online databases (PubMed/Medline, Web of Science, Scopus and Embase) in order to identify suitable publications for inclusion in the meta-analysis. Results were expressed as weighted mean differences (WMD).

RESULTS

From 12343 articles identified in different databases, a total of 7 RCT arms were entered into the quantitative synthesis. The manuscripts were published between 2019 and 2023. IF regimens (the 5:2 diet, 16/8 time-restricting feeding, and alternate day fasting) varied from 2 months to 3 months. IF regimens reduced steatosis scores (WMD: -33.22 CAP dB/m, 95 % CI: -50.72 to -15.72), anthropometric characteristics of obesity (WMD: -0.77 kg/m2, 95 % CI: -1.38 to -0.17 for body mass index; WMD: -3.16 kg, 95 % CI: -4.71 to -1.61 for body weight; WMD: -1.90 kg, 95 % CI: -3.51 to -0.29 for waist circumference), as well as ALT (WMD: -9.10 U/L, 95 % CI: -12.45 to -5.75), triglyceride (WMD: -20.83 mg/dl, 95 % CI: -39.01 to -2.66), total cholesterol (WMD: -7.80 mg/dl, 95 % CI: -15.18), HbA1c (WMD: -0.14 %, 95 % CI: -0.20 to -0.08) and HOMA-IR (WMD: -1.21, 95 % CI: -2.08 to -0.34) levels versus controls. Nevertheless, no between-group differences were detected for other biomarkers, e.g., fasting blood glucose, insulin, AST, HDL-C or LDL-C values, and fibrosis scores.

CONCLUSION

IF regimens can improve some markers of cardiometabolic and liver function in patients with NAFLD. However, the available evidence to support the benefits of IF regimens is limited and derived from a small number of studies, thus further research is needed to clarify the impact of IF on the cardiometabolic health of NAFLD patients.

Effects of intermittent fasting combined with physical exercise on cardiometabolic outcomes: systematic review and meta-analysis of clinical studies

CONTEXT

Different intermittent fasting (IF) protocols have been proven to be efficient in improving cardiometabolic markers, but further research is needed to examine whether or not combining IF regimens plus physical exercise is superior to control diets (ie, nonfasting eating) plus physical exercise in this setting.

OBJECTIVE

The aim of this study was to determine whether or not combining IF plus exercise interventions is more favorable than a control diet plus exercise for improving cardiometabolic health outcomes.

DATA SOURCE

PubMed, Scopus, and Web of Science were comprehensively searched until April 2023.

DATA EXTRACTION

Electronic databases were searched for clinical trials that determined the effect of IF plus exercise vs a control diet plus exercise on body weight, lipid profile (high-density lipoprotein [HDL], low-density lipoprotein [LDL], triglycerides, and total cholesterol), and systolic and diastolic blood pressure (SBP and DBP, respectively). Analyses were conducted for IF plus exercise vs a nonfasting diet plus exercise to calculate weighted mean differences (WMDs).

DATA ANALYSIS

The meta-analysis included a total of 14 studies, with a total sample of 360 adults with or without obesity. The duration ranged from 4 to 52 weeks. IF plus exercise decreased body weight (WMD = -1.83 kg; P = 0.001), LDL (WMD = -5.35 mg/dL; P = 0.03), and SBP (WMD = -2.99 mm Hg; P = 0.003) significantly more than a control diet plus exercise. HDL (WMD = 1.57 mg/dL; P = 0.4) and total cholesterol (WMD = -2.24 mg/dL; P = 0.3) did not change significantly for IF plus exercise vs a control diet plus exercise, but there was a trend for reducing triglycerides (WMD = -13.13 mg/dL; P = 0.07) and DBP (WMD = 2.13 mm Hg; P = 0.05), which shows clinical magnitude.

CONCLUSION

IF plus exercise improved some cardiometabolic outcomes (body weight, blood pressure, and lipid profile) compared with a control diet plus exercise.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023423878.

Early Pharmacologic Approaches to Avert Anabolic Steroid-induced Male Infertility: A Narrative Review

PURPOSE

To review the impact of testosterone and other androgenic-anabolic steroids (AASs) on male fertility, exploring potential drugs that can be used to preserve or restore male fertility upon AAS use or prior contact.

METHODS

A review was performed to provide a unifying clinical link between drugs used to preserve or restore male fertility (ie, clomiphene citrate, human chorionic gonadotropin, selective estrogen receptor modulators, recombinant luteinizing and follicle-stimulating hormones, and human menopausal gonadotrophin) in the context of AAS-induced infertility and related aspects.

FINDINGS

Human chorionic gonadotropin (125-500 IU every other day), clomiphene citrate (12.5-50 mg/d), recombinant luteinizing hormone (125-500 IU every other day), recombinant follicle-stimulating hormone (75-150 IU 1-3×/wk), and human menopausal gonadotrophin (75-150 IU 1-3×/wk) are promising early pharmacologic approaches to avert AAS-induced male infertility. Additionally, a full partner assessment is crucial to the success of a couple planning to have children. The partner's age and gynecopathies must be considered. Egg or sperm cryopreservation can also be alternatives for future fertility. Reinforcing AAS cessation is imperative to achieving better success in misusers.

IMPLICATIONS

The exponential increase in AAS misuse raises concerns about the impact on male fertility. This review suggests that gonadotropin analogs and selective androgen receptor modulators (clomiphene citrate) are viable approaches to early preserve or restore fertility in men on AAS use or with previous contact. However, proper standardization of doses and combinations is required and hence physicians should also be aware of patients' and partners' fertility.

Intermittent fasting in the management of diabetes: a review of glycemic control and safety

Intermittent fasting (IF) regimens have emerged as a dietary tool to improve the glycemic profile, but a critical appraisal of clinical studies assessing the effects of IF regimens in patients with diabetes is needed. Thus, this review encompasses clinical studies examining the impact of different IF regimens on markers of glycemic control in patients with diabetes. Furthermore, clinical nuances relative to pharmacological treatment are also addressed, mainly insulin therapy, to discuss the risk of hypoglycemic events. Only a handful of clinical studies have investigated the effects of IF on patients with diabetes. Overall, IF regimens may elicit modest benefits on glycemic parameters in patients with diabetes, but their effects are not necessarily greater than those of control diets. Last, although IF regimens may be considered safe for patients receiving insulin therapy within interventional and observational research, markers of glycemic control must be constantly monitored in clinical practice to reduce the risk of hypoglycemia and its related complications.

Cholesterol intake and serum total cholesterol levels are not associated with total testosterone levels in men: a cross-sectional study from NHANES 2013-2014

BACKGROUND

Testosterone (T) is an anabolic hormone crucial to the structure and function of skeletal muscle. Testosterone is partially synthesized from cholesterol, but little is known about the relationship of cholesterol intake and serum cholesterol with T levels.

AIM

To investigate whether cholesterol intake and serum total cholesterol (TC) levels are associated with serum total testosterone (TT) levels in men.

METHODS

A cross-sectional study enrolling 1996 men aged 20 to 80 years from National Health and Nutrition Examination Survey (NHANES) 2013-2014 was carried out. Diet assessment was performed using two 24-h food recalls, and TT levels were measured by liquid chromatography coupled with tandem mass spectrometry. Regression analyses were performed to evaluate whether TT was associated with cholesterol intake and serum TC levels.

RESULTS

Neither cholesterol intake nor serum TC levels were associated with TT levels in unadjusted and adjusted analyses (adjustment for energy, total fat and alcohol intake, smoking, age, physical activity, family income, marital status, race, educational level, diabetes, hypertension, and body mass index).

CONCLUSION

Dietary cholesterol intake and TC levels are not associated with TT levels in men from the USA.

Association between dietary glycemic index and non-alcoholic fatty liver disease in patients with type 2 diabetes mellitus

Objective

Managing dietary glycemic index (GI) deserves further attention in the interplay between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). This study aimed to evaluate the relationship between dietary GI and the odds of NAFLD in patients with T2DM.

Methods

A cross-sectional study was carried out between April 2021 and February 2022, including 200 participants with T2DM aged 18-70 years, of which 133 had NAFLD and 67 were in the non-NAFLD group. Cardiometabolic parameters were analyzed using standard biochemical kits and dietary intake was assessed using a validated food frequency questionnaire. Binary logistic regression was applied to explore odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD according to tertiles of dietary GI.

Results

Highest vs. lowest tertile (< 57 vs. > 60.89) of energy-adjusted GI was not associated with the odds of having NAFLD (OR 1.25, 95% CI = 0.6-2.57; P-trend = 0.54) in the crude model. However, there was an OR of 3.24 (95% CI = 1.03-10.15) accompanied by a significant trend (P-trend = 0.04) after full control for potential confounders (age, gender, smoking status, duration of diabetes, physical activity, waist circumference, HbA1c, triglycerides, total cholesterol, dietary intake of total carbohydrates, simple carbohydrates, fat, and protein).

Conclusion

High dietary GI is associated with increased odds of NAFLD in subjects with T2DM. However, interventional and longitudinal cohort studies are required to confirm these findings.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

Legume Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

There is an equivocal and inconsistent association between legume consumption and health outcomes and longevity. The purpose of this study was to examine and quantify the potential dose-response relationship between legume consumption and all-cause and cause-specific mortality in the general population. We conducted a systematic literature search on PubMed/Medline, Scopus, ISI Web of Science, and Embase from inception to September 2022, as well as reference lists of relevant original papers and key journals. A random-effects model was used to calculate summary HRs and their 95% CIs for the highest and lowest categories, as well as for a 50 g/d increment. We also modeled curvilinear associations using a 1-stage linear mixed-effects meta-analysis. Thirty-two cohorts (31 publications) involving 1,141,793 participants and 93,373 deaths from all causes were included. Higher intakes of legumes, compared with lower intakes, were associated with a reduced risk of mortality from all causes (HR: 0.94; 95% CI: 0.91, 0.98; n = 27) and stroke (HR: 0.91; 95% CI: 0.84, 0.99; n = 5). There was no significant association for CVD mortality (HR: 0.99; 95% CI: 0.91, 1.09; n =11), CHD mortality (HR: 0.93; 95% CI: 0.78, 1.09; n = 5), or cancer mortality (HR: 0.85; 95% CI: 0.72, 1.01; n = 5). In the linear dose-response analysis, a 50 g/d increase in legume intake was associated with a 6% reduction in the risk of all-cause mortality (HR: 0.94; 95% CI: 0.89, 0.99; n = 19), but no significant association was observed for the remaining outcomes. The certainty of evidence was judged from low to moderate. A higher legume intake was associated with lower mortality from all causes and stroke, but no association was observed for CVD, CHD, and cancer mortality. These results support dietary recommendations to increase the consumption of legumes.

Eating more sardines instead of fish oil supplementation: Beyond omega-3 polyunsaturated fatty acids, a matrix of nutrients with cardiovascular benefits

Omega-3 polyunsaturated fatty acids (n-3 PUFA) play a significant role in the prevention and management of cardiometabolic diseases associated with a mild chronic pro-inflammatory background, including type 2 diabetes, hypertension, hypertriglyceridaemia, and fatty liver disease. The effects of n-3 PUFA supplements specifically, remain controversial regarding reducing risks of cardiovascular events. n-3 PUFA supplements come at a cost for the consumer and can result in polypharmacy for patients on pharmacotherapy. Sardines are a well-known, inexpensive source of n-3 PUFA and their consumption could reduce the need for n-3 PUFA supplementation. Moreover, sardines contain other cardioprotective nutrients, although further insights are crucial to translate a recommendation for sardine consumption into clinical practice. The present review discusses the matrix of nutrients contained in sardines which confer health benefits for cardiometabolism, beyond n-3 PUFA. Sardines contain calcium, potassium, magnesium, zinc, iron, taurine, arginine and other nutrients which together modulate mild inflammation and exacerbated oxidative stress observed in cardiovascular disease and in haemodynamic dysfunction. In a common serving of sardines, calcium, potassium, and magnesium are the minerals at higher amounts to elicit clinical benefits, whilst other nutrients are present in lower but valuable amounts. A pragmatic approach towards the consumption of such nutrients in the clinical scenario should be adopted to consider the dose-response relationship effects on physiological interactions. As most recommendations currently available are based on an indirect rationale of the physiological actions of the nutrients found in sardines, randomised clinical trials are warranted to expand the evidence on the benefits of sardine consumption.

Effects of time-restricted feeding (16/8) combined with a low-sugar diet on the management of non-alcoholic fatty liver disease: A randomized controlled trial

OBJECTIVES

Emerging studies have employed time-restricted feeding (TRF) and a low-sugar diet alone in the management of non-alcoholic fatty liver disease (NAFLD), but their combination has not been tested. The aim of this study was to investigate the effects of TRF combined with a low-sugar diet on NAFLD parameters, cardiometabolic and inflammatory biomarkers, and body composition in patients with NAFLD.

METHODS

A 12-wk randomized controlled trial was performed to compare the effects of TRF (16 h fasting/8 h feeding daily [16/8]) plus a low-sugar diet versus a control diet based on traditional meal distribution in patients with NAFLD. Changes in body composition, anthropometric indices, and liver and cardiometabolic markers were investigated.

RESULTS

TRF 16/8 with a low-sugar diet reduced body fat (26.7 ± 5.4 to 24.2 ± 4.9 kg), body weight (83.8 ± 12.7 to 80.5 ± 12.1 kg), waist circumference (104.59 ± 10.47 to 101.91 ± 7.42 cm), and body mass index (29.1 ± 2.6 to 28 ± 2.7 kg/m²), as well as circulating levels of fasting blood glucose and liver (alanine aminotransferase, 34 ± 13.9 to 21.2 ± 5.4 U/L; aspartate aminotransferase, 26.3 ± 6.2 to 20.50 ± 4 U/L; γ-glutamyl transpeptidase, 33 ± 15 to 23.2 ± 11.1 U/L; fibrosis score, 6.3 ± 1 to 5.2 ± 1.2 kPa; and controlled attenuation parameter, 322.9 ± 34.9 to 270.9 ± 36.2 dB/m), lipids (triacylglycerols, 201.5 ± 35.3 to 133.3 ± 48.7 mg/dL; total cholesterol, 190 ± 36.6 to 157.8 ± 33.6 mg/dL; and low-density lipoprotein cholesterol, 104.6 ± 27.3 to 84 ± 26.3 mg/dL), and inflammatory markers (high-sensitivity C-reactive protein, 3.1 ± 1.1 to 2 ± 0.9 mg/L; and cytokeratin-18, 1.35 ± 0.03 to 1.16 ± 0.03 ng/mL). These results were statistically significant (P < 0.05) compared with the control group.

CONCLUSIONS

TRF plus a low-sugar diet can reduce adiposity and improve liver, lipid, and inflammatory markers in patients with NAFLD.

The effects of chitosan supplementation on anthropometric indicators of obesity, lipid and glycemic profiles, and appetite-regulated hormones in adolescents with overweight or obesity: a randomized, double-blind clinical trial

Background

Chitosan is one of dietary fiber that has received great attention in improving obesity-related markers, but little is known on its effects on adolescents.

Objectives

To analyze the effects of chitosan supplementation on obesity-related cardiometabolic markers and appetite-related hormones in adolescents with overweight or obesity.

Methods and analysis

A randomized clinical trial was performed on 64 adolescents with overweight and obesity, who were randomly allocated to receive chitosan supplementation (n = 32) or placebo as control (n = 32) for 12 weeks. Anthropometric measures, lipid and glycemic profiles, and appetite-related hormones were examined.

Results

Sixty-one participants completed study (chitosan = 31, placebo = 30). Chitosan supplementation significantly improved anthropometric indicators of obesity (body weight: − 3.58 ± 2.17 kg, waist circumference: − 5.00 ± 3.11 cm, and body mass index: − 1.61 ± 0.99 kg/m² and − 0.28 ± 0.19 Z-score), lipid (triglycerides: − 5.67 ± 9.24, total cholesterol: − 14.12 ± 13.34, LDL-C: − 7.18 ± 10.16, and HDL-C: 1.83 ± 4.64 mg/dL) and glycemic markers (insulin: − 5.51 ± 7.52 μIU/mL, fasting blood glucose: − 5.77 ± 6.93 mg/dL, and homeostasis model assessment of insulin resistance: − 0.24 ± 0.44), and appetite-related hormones (adiponectin: 1.69 ± 2.13 ng/dL, leptin − 19.40 ± 16.89, and neuropeptide Y: − 41.96 ± 79.34 ng/dL). When compared with the placebo group, chitosan supplementation had greater improvement in body weight, body mass index (kg/m² and Z-score), waist circumference, as well as insulin, adiponectin, and leptin levels. Differences were significant according to P-value < 0.05.

Conclusion

Chitosan supplementation can improve cardiometabolic parameters (anthropometric indicators of obesity and lipid and glycemic markers) and appetite-related hormones (adiponectin, leptin, and NPY) in adolescents with overweight or obesity.

Effects of the 5:2 intermittent fasting diet on non-alcoholic fatty liver disease: A randomized controlled trial

Background and aims

Dietary regimens are crucial in the management of non-alcoholic fatty liver disease (NAFLD). The effects of intermittent fasting (IF) have gained attention in this regard, but further research is warranted. Thus, we aimed to ascertain the overall effects of the 5:2 IF diet (5 days a week of normal food intake and 2 consecutive fasting days) in patients with NAFLD compared to a control group (usual diet).

Methods and results

A 12-week randomized controlled trial was performed to evaluate the effects of the 5:2 IF diet on anthropometric indices, body composition, liver indices, serum lipids, glucose metabolism, and inflammatory markers in patients with NAFLD. The IF group (n = 21) decreased body weight (86.65 ± 12.57–82.94 ± 11.60 kg), body mass index (30.42 ± 2.27–29.13 ± 1.95 kg/m²), waist circumference (103.52 ± 6.42–100.52 ± 5.64 cm), fat mass (26.64 ± 5.43–23.85 ± 5.85 kg), fibrosis (6.97 ± 1.94–5.58 ± 1.07 kPa), steatosis scores/CAP (313.09 ± 25.45–289.95 ± 22.36 dB/m), alanine aminotransferase (41.42 ± 20.98–28.38 ± 15.21 U/L), aspartate aminotransferase (34.19 ± 10.88–25.95 ± 7.26 U/L), triglycerides (171.23 ± 39.88–128.04 ± 34.88 mg/dl), high-sensitivity C-reactive protein (2.95 ± 0.62 −2.40 ± 0.64 mg/L), and cytokeratin-18 (1.32 ± 0.06–1.19 ± 0.05 ng/ml) values compared to the baseline and the end of the control group (n = 23)—p ≤ 0.05 were considered as significant. However, the intervention did not change the levels of high-density lipoprotein cholesterol, total cholesterol, low-density lipoprotein cholesterol, fasting blood sugar, insulin, HOMA-IR, and total antioxidant capacity.

Conclusion

Adhering to the 5:2 IF diet can reduce weight loss and related parameters (fat mass and anthropometric indicators of obesity), as well as hepatic steatosis, liver enzymes, triglycerides, and inflammatory biomarkers in patients with NAFLD.

Associations of the Paleolithic Diet Pattern Scores and the Risk of Breast Cancer among Adults: A Case-Control Study

Evidence suggests the role of changing traditional lifestyle patterns such as Paleolithic to modern lifestyle in the incidence and epidemic of chronic diseases. Thus, this study aimed to investigate the association between Paleolithic diet (PD) and risk of Breast Cancer (BC) in adult Iranian women. This matched case-control study included 253 women with BC and 267 healthy women aged >18 years. PD score was evaluated using a validated 168-item quantitative food frequency questionnaire. Conditional logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs), and dose-response was investigated. Mean of PD score was 39.00 ± 6.39. Among the food groups of the PD components, BC patients significantly had lower consumption of healthy food groups as vegetables, fruits, fish, and nuts, higher intakes of sugar-sweetened beverages as well as grains and starches. After adjustment for potential confounders, comparing the highest quartile of PD scores with the lowest quartile, a decrease in the risk of BC was observed for all women (OR: 0.26; 95% CI: 0.13-0.53), as well as those premenopausal (OR: 0.29; 95% CI: 0.11), and postmenopausal (OR: 0.17; 95% CI: 0.05 - 0.56). Our findings show that adherence to the PD pattern significantly reduces the risk of BC in the population studied. However, prospective studies are needed to further investigate this association.

Higher Adherence to the Mediterranean Dietary Pattern Is Inversely Associated With Severity of COVID-19 and Related Symptoms: A Cross-Sectional Study

Background and Aims

Adherence to the Mediterranean diet (MD) has been associated with a decreased risk of developing a variety of chronic diseases that are comorbidities in COVID-19 patients. However, its association to the severity and symptoms of COVID-19 are still unknown. This study aimed to examine the association between adherence to the MD pattern and COVID-19 severity and symptoms in Iranian hospitalized patients.

Methods

In this cross-sectional study, 250 COVID-19 patients aged 18 to 65 were examined. We employed a food frequency questionnaire (FFQ) to obtain data on dietary intake of participants in the year prior to their COVID-19 diagnosis. COVID-19 severity was determined using the National Institutes of Health's Coronavirus Disease 2019 report. Additionally, symptoms associated with COVID-19, inflammatory markers, and other variables were evaluated. The scoring method proposed by Trichopoulou et al. was used to assess adherence to the MD.

Results

The participants' mean age was 44.1 ± 12.1 years, and 46% of them had severe COVID-19. Patients who adhered more closely to the MD had lower serum C-reactive protein levels (7.80 vs. 37.36 mg/l) and erythrocyte sedimentation rate (14.08 vs. 42.65 mm/h). Those with the highest MD score were 77% less likely to have severe COVID-19 after controlling for confounding variables. The MD score was also found to be inversely associated with COVID-19 symptoms, including dyspnea, cough, fever, chills, weakness, myalgia, nausea and vomiting, and sore throat.

Conclusion

Higher adherence to the MD was associated with a decreased likelihood of COVID-19 severity and symptoms, as well as a shorter duration of hospitalization and convalescence, and inflammatory biomarkers.

Nonpharmacological Interventions for the Management of Testosterone and Sperm Parameters: A Scoping Review

PURPOSE

Testosterone replacement and associated pharmacologic agents are effective strategies to treat male hypogonadism; however, nutraceutical agents and lifestyle modification approaches have gained medical interest. The purpose of this scoping review is to highlight the evidence (or lack thereof) of nutraceuticals and lifestyle modification approaches in the management of testosterone levels and sperm parameters.

METHODS

A scoping review of nonpharmacologic interventions (supplements, herbal medicines, diets, sleep, and exercise) with the potential to improve male health was undertaken to elucidate changes in testosterone levels and sperm parameters in men with hypogonadism or infertility compared with healthy patients.

FINDINGS

A multitude of nutraceuticals and functional nutrients are purported to stimulate testosterone production; however, only a select few have had promising results, such as zinc, vitamin D (in case of hypovitaminosis D), l-arginine, mucuna, and ashwagandha, based on well-controlled randomized clinical trials of men with low testosterone levels and related problems. Except for l-arginine, these natural agents, as well as tribulus and ω3 fatty acids, can improve some degree of sperm parameters in infertile men. Before implementing these nutraceutical agents, adequate sleep, exercise, and weight loss in patients with obesity are imperative. The effects of nonpharmacologic interventions on testosterone levels are modest and hence do not directly translate into clinical benefits. Correspondingly, androgen receptor content, but not endogenous androgens, has been regarded as the principal factor in muscle hypertrophy.

IMPLICATIONS

A limited number of supplements and herbal medicines can be considered as adjunctive approaches in the management of testosterone levels and sperm parameters, primarily in men with low testosterone levels and infertility, whereas most nonpharmacologic supplements appear to lack evidence. Although proper physical exercise, sleep, and diet are indisputable approaches because of the general benefits to health, the use of nutraceuticals, if considered, must be personalized by physicians and/or registered dietitians.

Higher dietary total antioxidant capacity is inversely associated with Helicobacter pylori infection among adults: A case-control study

INTRODUCTION

Antioxidants appear to hinder the actions of Helicobacter pylori (H. pylori). The aim of this research was to evaluate the association between dietary total antioxidant capacity (DTAC) and H. pylori infection.

METHODS

A case-control study was carried out among 200 patients with  H. pylori infection and 402 healthy subjects (18-55 years). Dietary data were collected using a validated 168-item quantitative food frequency questionnaire. DTAC was calculated based on the oxygen radical absorbance capacity of each food (except for coffee) reported by the US Department of Agriculture.

RESULTS

Compared with participants in the lowest tertile of DTAC, those in the highest tertile had a significantly lower odds ratio (OR) in the crude model (OR, 0.29; 95% CI, 0.14-0.61; p for trend = 0.001), model 1 (adjustment for age and sex) (OR, 0.37; 95% CI, 0.24-0.58; p for trend < 0.001), and model 2 (adjustment for model 1 plus body mass index, waist circumference, physical activity, smoking, dietary intake of energy and fat) (OR, 0.20; 95% CI, 0.10-0.40; p for trend ≤ 0.001).

CONCLUSIONS

A high DTAC is associated with a reduced risk of H. pylori infection in adults. Further studies are mandatory to elucidate the mechanisms and a dose-effect relationship.

Higher Intake of Dietary Magnesium Is Inversely Associated With COVID-19 Severity and Symptoms in Hospitalized Patients: A Cross-Sectional Study

Background and Aims

Magnesium is an anti-inflammatory mineral that plays a role in the innate immune system, and the relaxation of bronchial smooth muscle warrants additional attention in COVID-19. This study examined the association between magnesium intake and COVID-19 severity and related symptoms in hospitalized patients.

Methods

A cross-sectional study was done enrolling 250 COVID-19 patients aged 18 to 65 years. A validated 168-item online food frequency questionnaire (FFQ) was used to assess dietary magnesium intake. COVID-19 Treatment Guidelines were used to determine COVID-19 severity, and symptoms were evaluated using a standard questionnaire. Crude and adjusted analyses were performed (Model 1: age, sex, and energy intake; Model 2: Model 1 + physical activity, supplements, corticosteroids, and antiviral drugs; Model 3: Model 2 + body mass index).

Results

The mean age of participants was 44.1 ± 12.1 years, and 46% of them had severe COVID-19. Patients at the highest tertile of dietary magnesium intake had lower serum levels of inflammatory biomarkers, including CRP (11.8 ± 2.2 vs. 29.5 ± 2.1 mg/L, p < 0.001) and ESR (15.8 ± 2.4 vs. 34.7 ± 2.4 mm/hr, p < 0.001), than those at the lowest tertile. After controlling for potential confounders, we observed that a higher dietary magnesium intake was associated with a lower odds of severe COVID-19 (OR: 0.32; 95% CI: 0.15–0.70). Also, we found a significant inverse association between dietary magnesium intake and odds of COVID-19 symptoms.

Conclusion

We found that higher intake of dietary magnesium was inversely associated with COVID-19 severity and symptoms.

Effects of probiotic supplementation on abdominal pain severity in pediatric patients with irritable bowel syndrome: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome (IBS), but the evidence is not compelling. Thus, a systematic review and meta-analysis of randomized clinical trials (RCTs) were performed to investigate the effects of probiotic supplementation on abdominal pain in pediatric patients with IBS.

METHODS

PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, and Embase were the available databases searched to find relevant randomized clinical trials up to April 2021. The effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

Seven RCTs with 441 participants were included, from which the meta-analysis demonstrated that probiotic supplementation has a significant effect on reducing abdominal pain in pediatric patients with IBS (WMD = - 2.36; 95% CI - 4.12 to - 0.60; P = 0.009). Although our study involved children and adolescents (≤ 18 years), the effects of probiotic supplementation seem to be more potent in patients under 10 years old (WMD = - 2.55; 95% CI - 2.84 to - 2.27) compared to patients aged 10-18 years (WMD = - 1.70; 95% CI - 2.18 to - 1.22). The length of supplementation longer than four weeks was more effective (WMD = - 2.43; 95% CI - 2.76 to - 2.09).

CONCLUSION

Probiotic supplementation can reduce abdominal pain in pediatric patients with IBS.

A scoping review of intermittent fasting, chronobiology, and metabolism

Chronobiology plays a crucial role in modulating many physiologic systems in which there is nutritional synergism with meal timing. Given that intermittent fasting (IF) has grown as a flexible dietary method consisting of delayed or early eating windows, this scoping review addresses the effects of IF protocols on metabolism as they relate to clinical nutrition and the circadian system. Although nocturnal habits are associated with circadian misalignments and impaired cardiometabolic profile-and nutritional physiology is better orchestrated during the day-most findings are based on animal experiments or human studies with observational designs or acute meal tests. Well-controlled randomized clinical trials employing IF protocols of delayed or early eating windows have sometimes demonstrated clinical benefits, such as improved glycemic and lipid profiles, as well as weight loss. However, IF does not appear to be more effective than traditional diets at the group level, and its effects largely depend on energy restriction. Thus, efforts must be made to identify patient biological rhythms, preferences, routines, and medical conditions before individual dietary prescription in clinical practice.

Does tibolone treatment have favorable effects on obesity, blood pressure, and inflammation? A meta-analysis of randomized controlled trials

The clinical effects of tibolone on cardiometabolic markers are an underlying question in postmenopausal women. We aimed to meta-analyze the effects of tibolone on anthropometric indicators of obesity, blood pressure (BP), and on C-reactive protein (CRP) levels in postmenopausal women. Two independent reviewers searched Scopus, Web of Science, PubMed/Medline, and Embase up to until 20 April 2021. Weighted mean differences (WMDs) and 95% confidence interval (CI) were calculated through the DerSimonian and Laird random-effect models between the tibolone and the control groups. Data from 20 eligible included showed that tibolone treatment increased the body mass index (BMI) by 0.23 kg/m² (95% CI: 0.017 to 0.45, p = 0.03) but did not significantly increase body weight (WMD: 1.128 kg, 95% CI: -1.76 to 4.02, p = 0.44) or waist circumference (WC) (WMD: 0.64 cm, 95% CI: -3.18 to 4.48, p = 0.74). Also, tibolone treatment neither changed the systolic BP (WMD: 2.60 mmHg, 95% CI: -2.52 to 7.72, p = 0.31) nor the diastolic BP (WMD: 0.711 mmHg, 95% CI: -2.52 to 3.94, p = 0.66), but increased CRP levels by 0.44 mg/L (95% CI: 0.10 to 0.78, p = 0.01). Tibolone treatment administered in postmenopausal women increased BMI and CRP but did not change body weight, WC, and SBP. Diastolic BP decreased after the tibolone intervention only in the studies lasting 26 weeks versus ˃26 weeks.

Effects of guar gum supplementation on the lipid profile: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Guar gum can be used as an adjuvant in the treatment of dyslipidemia. However, based on data from different studies, the effectiveness of this product is not uniform. Therefore, we conducted a dose-response meta-analysis between guar gum supplementation and lipid profile.

METHODS AND RESULTS

Five databases (Scopus, Web of Science, PubMed/Medline, Embase, and Google Scholar) were searched to identify relevant articles published up to July 2020. The weighted mean difference (WMD) was derived based on the random-effects model. Overall findings were generated from 25 eligible trials. Patients' conditions included hyperlipidemia, diabetes, metabolic syndrome, hypertension, overweight, carotid endarterectomy, and menopausal women. Prescribed gum dose varied between 100 mg/d and 30 g/d for 1-24 months. Compared with control groups, guar gum supplementation decreased total cholesterol (TC) by -20.41 mg/dL (95% CI: -26.76 to -14.07; P < 0.001) and low-density lipoprotein-cholesterol (LDL-C) by -17.37 mg/dL (95% CI: -23.60 to -11.13; P < 0.001), but did not change triglycerides (TG) (WMD: -6.53 mg/dL, 95% CI: -16.03 to 2.97; P = 0.178) and high-density lipoprotein-cholesterol (HDL-C) (WMD: -0.62 mg/dL, 95% CI: -1.68 to 0.44, P = 0.252).

CONCLUSIONS

Guar gum supplementation significantly reduced serum LDL-C and TC levels in patients with cardiometabolic problems, but had neutral effects on TG and HDL-C levels.

Effects of dehydroepiandrosterone (DHEA) supplementation on cortisol, leptin, adiponectin, and liver enzyme levels: A systematic review and meta-analysis of randomised clinical trials

BACKGROUND AND AIMS

Dehydroepiandrosterone (DHEA) supplementation has been investigated in patients with altered cortisol levels and is proposed to ameliorate the metabolic profile related to adipose tissue. However, further research is warranted and evidence is no compelling for liver safety. Hence, we aimed to meta-analyse the effects of DHEA supplementation on circulating levels of cortisol, liver enzymes, and adipokines.

METHODS

We searched literature published in PubMed, Web of Science, Embase and Scopus, until December 2020. We obtained overall results using the generic inverse of variance method with a random-effects model.

RESULTS

Through 10 arms, serum cortisol levels decreased significantly after DHEA supplementation [weighted mean difference (WMD): -53.581 nmol/L, 95% confidence interval (CI): -88.2, -18.9, P = .002], without significant heterogeneity (I²  = 36%, P = .117). In contrast, any significance was noted for adiponectin (WMD: -0.045 µg/mL, 95% CI: -0.56, 0.47; P = .865), leptin (WMD: -2.55 µg/mL, 95% CI: -6.2, 1.06; P = .166), aspartate transaminase (AST) (WMD: -3.7 U/L, 95% CI: -10.35, 2.95; P = .276), and alanine aminotransferase (ALT) (WMD: -1.7 U/L, 95% CI: -3.45, 0.06; P = .058).

CONCLUSION

DHEA supplementation decreased circulating cortisol but did not alter adiponectin, leptin, AST, and ALT levels. Hence, DHEA supplementation could be considered as an adjunct in the management of hypercortisolaemia and is safe for the liver.

Effect of sleep duration on dietary intake, desire to eat, measures of food intake and metabolic hormones: A systematic review of clinical trials

BACKGROUND AND AIMS

Sleep, as well as diet and physical activity, plays a significant role in growth, maturation, health, and regulation of energy homeostasis. Recently, there is increasing evidence indicating a possible causal association between sleep duration and energy balance. We aimed to examine the relationship between sleep duration and food consumption, energy intake, anthropometric characteristics, and appetite-regulating hormones by randomized controlled trials (RCTs).

METHODS

Electronic literature searches were conducted on Medline, Web of Science, and Google Scholar until July 2020. The search was conducted with the following words: "Sleep Duration", "Circadian Rhythm", "Sleep Disorders" in combination with "Obesity", "Overweight", "Abdominal Obesity", "Physical Activity", "Energy Intake", "Body Mass Index", "Lipid Metabolism", "Caloric Restriction", Leptin, "Weight Gain", and "Appetite Regulation" using human studies.methods RESULTS: After screening 708 abstracts, 50 RCTs (7 on children or adolescents and 43 on adults) were identified and met the inclusion criteria. In general, the findings suggested that sleep restriction may leads to a significant increment in energy intake, fat intake, body weight, appetite, hunger, eating occasions, and portion size, while protein and carbohydrate consumption, total energy expenditure, and respiratory quotient remained unaffected as a result of sleep restriction. Serum leptin, ghrelin, and cortisol concentrations were not influenced by sleep duration as well.

CONCLUSION

Insufficient sleep can be considered as a contributing factor for energy imbalance, weight gain, and metabolic disorders and it is suggested that to tackle disordered eating it may be necessary to pay more attention to sleep duration.

Effects of raloxifene administration on serum levels of insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 levels: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To ascertain the clinical magnitude of raloxifene administration on insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) levels.

METHODS

A systematic comprehensive search was performed without language limitation up to 14 December 2020. We included only trials that assessed the effect of raloxifene on IGF-1 and IGFBP-3 in adults. Meta-analysis was performed using the Stata software (Stata Corp. College Station, Texas, USA).

RESULTS

Seven arms were included, encompassing postmenopausal women with type 2 diabetes mellitus, postmenopausal women with breast cancer, healthy postmenopausal women, and healthy elderly men. Raloxifene therapy significantly reduced IGF-1 levels (WMD: -2.92 nmol/L, 95% CI: -3.49, -2.35, p < 0.001) compared to placebo. Raloxifene dosage ˃60 mg/day (WMD: -3.29 ng/mL, 95% CI: -3.50 to -3.08, I² = 0.0%) decreased IGF-1 levels more than 60 mg/day (WMD: -2.29 ng/mL, 95% CI: -2.90 to -1.69, I² = 16%). Moreover, intervention duration ˃26 weeks (WMD: -3.48 ng/mL, 95% CI: -5.26 to -1.69, I² = 0.0%) reduced IGF-1 levels more than ˂26 weeks (WMD: -2.55 ng/mL, 95% CI: -3.31 to -1.79, I² = 92%). In contrast, overall results from the random-effects model did not suggest a significant change in IGFBP-3 levels upon raloxifene therapy.

CONCLUSION

Raloxifene therapy significantly reduced serum levels of IGF-1 levels but without changes in IGFPB-3 levels.

The effects of the Dietary Approaches to Stop Hypertension (DASH) diet on metabolic risk factors in patients with chronic disease: A systematic review and meta-analysis of randomized controlled trials

AIMS

The DASH diet was designed for helping control of blood pressure but, fortunately, it can also be prescribed for many other chronic conditions. The current study intended to assess the potential effects of DASH diet on metabolic risk factors in patients with chronic disease.

DATA SYNTHESIS

We carried out a systematic literature search for RCTs from inception until July 2020. A total of 54 clinical trials were included in the final analysis. Compared to control groups, a significant lower effect of the DASH diet was noted for body weight (-1.59 kg; p < 0.001), BMI (-0.64 kg/m²; p < 0.001), and WC (-1.93 cm; p < 0.001) as well as for SBP (-3.94 mmHg; p < 0.001) and DBP (-2.44 mmHg; P < 0.001). The DASH diet significantly decreased TC (-5.12 mg/dl; p = 0.008) and LDL-C levels (-3.53 mg/dl; p = 0.041), but not HDL-C (0.30 mg/dl; p = 0.510), TG (-4.22 mg/dl; p = 0.067), and VLDL-C (-2.16 mg/dl; p = 0.062). No significant effect of the DASH diet was noted for blood glucose (-0.38 mg/dl; p = 0.216), insulin (-0.03 μIU/mL; p = 0.817), HOMA-IR (-0.15; p = 0.132), and CRP (-0.33 mg/l; p = 0.173).

CONCLUSIONS

The DASH diet is a feasible approach to weight loss and to control blood pressure and hypercholesterolemia.

Higher intakes of dietary caffeine are associated with 25-hydroxyvitamin D deficiency

Low serum 25-hydroxyvitamin D [25(OH)D] levels remain a challenge worldwide. While some in vitro studies show a caffeine-induced decrease in vitamin D receptor expression, there is a paucity of research to define the extent of caffeine intake on 25(OH)D levels. Therefore, we aimed to associate dietary caffeine intake with 25(OH)D deficiency through a recognized dataset. Using data collected from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), 25(OH)D levels and dietary caffeine intake were extracted from 13134 individuals (30-47 years, interquartile range). We used one-way ANOVA and chi-square tests for quantitative and qualitative variables, respectively, and performed multivariate logistic regression for four models to assess the odds ratio (OR) of 25(OH)D deficiency (<20 ng/ml or <50 nmol/L) based on quartiles of dietary caffeine intake. Both crude and multivariable models detected higher OR for 25(OH)D deficiency according to the highest intakes of caffeine (15.8±9.5, 51.9±11.9, and 177±156 mg/d) when compared to the reference category (2.19±1.04 mg/d), in which the OR in the highest category of caffeine intake was 1.24 (95% CI: 1.12 to 1.37) and 1.48 (95% CI: 1.16 to 1.78) for the crude model and the most complete multivariable analysis (adjustment for age, sex, race, body mass index, smoking, physical activity, occupation, energy intake, protein intake, and fat intake), respectively. In conclusion, higher dietary intakes of caffeine were associated with 25(OH)D deficiency in a representative sample of the American population, but further investigation is warranted to determine causation.

The Effect of Raloxifene Treatment on Lipid Profile in Elderly Individuals: A Systematic Review and Meta-analysis of Randomized Clinical Trials

PURPOSE

To perform a systematic review and meta-analysis of randomized clinical trials (RCTs) to elucidate the effects of raloxifene on the lipid profile in elderly individuals.

METHODS

A systematic review and meta-analysis of RCTs was performed following the PRISMA statement. Data on triglycerides (TGs), total cholesterol (TC), HDL-C, and LDL-C were extracted. Relevant publications up to October 2020 were detected through searches in the PubMed/MEDLINE, Web of Science, Scopus, and Embase databases. Changes were reported as weighted mean differences (WMDs) and 95% CIs using random-effects models.

FINDINGS

Nine studies were selected, with a duration of intervention ranging from 2 and 12 months and a raloxifene dose of 60 to 120 mg/d. Studies were performed in healthy individuals and in those with disorders, such as osteoporosis, type 2 diabetes, and kidney disease required long-term hemodialysis. Overall, TG (WMD, -6.50 mg/dL; 95% CI, -34.18 to 21.20 mg/eL; P = 0.646), LDL-C (WMD, -17.86 mg/dL; 95% CI, -42.44 to 6.72 mg/dL; P = 0.154), and HDL-C (WMD, 2.35 mg/dL; 95% CI, -1.14 to 5.84 mg/dL; P = 0.187) levels did not change significantly after the administration of raloxifene. In contrast, TC levels decreased after raloxifene therapy (WMD, -6.59 mg/dL; 95% CI, -13.13 to -0.05 mg/dL; P = 0.048).

IMPLICATIONS

Raloxifene therapy decreased TC levels but did not alter TG, HDL-C, and LDL-C concentrations in elderly individuals. Regarding the LDL-C levels, although the finding lacked statistical significance, we believe that there was a mean reduction that deserves further clinical attention as much as TC.

Therapeutic supplementation with zinc in the management of COVID-19-related diarrhea and ageusia/dysgeusia: mechanisms and clues for a personalized dosage regimen

Zinc supplementation is indicated for diarrhea and taste disorders, which are both features of COVID-19. Nevertheless, this strategy has not been tested for the treatment of these secondary complications in the current pandemic. Through an updated review, a practical appraisal was considered as a means of providing a medical nexus of therapeutic zinc regimens as an adjunct in the management of COVID-19–related diarrhea and ageusia/dysgeusia. While diarrhea and taste disorders are consequences of COVID-19, zinc supplementation is useful for non–COVID-19 patients with these clinical problems. The overwhelming evidence for supplementing with zinc in diarrhea and pneumonia is associated with the treatment of children, while for taste disorders the use of supplementing with zinc is more examined in adults. Whereas COVID-19 is more prevalent in adults, precautions should be exercised not to translate the zinc dosage used for children with diarrhea and taste disorders into the current pandemic. Therapeutic doses of zinc used for adults (∼50–150 mg/day of elemental zinc) could be included in the treatment strategies for COVID-19, but this proposal should be examined through randomized studies.

Does letrozole treatment have favorable effects on the lipid profile? A systematic review and meta-analysis of randomized clinical trials

As an aromatase inhibitor, letrozole reduces estrogen levels, affecting lipid indices because of the positive role of estrogens in modulating lipoproteins and lipids. Thus, our aim was to meta-analyze data regarding letrozole administration and its effects on the traditional lipid profile. A systematic review and meta-analysis of randomized clinical trials (RCTs) were performed based on the PRISMA guidelines. Web of Science, Scopus, PubMed/Medline, and EMBASE databases were searched until February 11, 2021. From 341 potentially relevant publications, 8 RCTs were selected. All studies used 2.5 mg/d of letrozole. Total cholesterol changed significantly by -6.28 mg/dL (95% CI: -8.73, -3.84, P < 0.001) and HDL-C by -4.40 mg/dL (95% CI: -5.30 to -3.50, p < 0.001) in letrozole group when compared to the control group. Taking into account this comparison between groups, in contrast, LDL-C (WMD: -2.50 mg/dL, 95% CI: -9.94, 4.93, p = 0.510) and triglycerides (WMD: -0.89 mg/dL, 95% CI: -6.87 to 5.07, p = 0.768) did not alter. In conclusion, letrozole administration decreased the concentrations of HDL-C and tocal cholesterol, but not of triglycerides and LDL-C.

Healthy Eating Index-2015 and Dietary Total Antioxidant Capacity as Predictors of Prediabetes: A Case-Control Study

BACKGROUND

The overall dietary quality, as well as the dietary total antioxidant capacity (DTAC), deserves central attention in the management of borderline high glucose levels since nonpharmacological strategies are imperative in this regard. Thus, we aimed to investigate the association between prediabetes with dietary quality and DTAC.

METHODS

A case-control study was conducted on 49 patients with prediabetes and 98 controls. Demographics, anthropometric measures, and fasting blood glucose levels of all participants were obtained. Participants completed a validated 80-item food frequency questionnaire (FFQ). DTAC scores were generated using FFQ data, and Healthy Eating Index-2015 (HEI-2015) was used as a diet quality index. The lowest tertile of HEI-2015 and DTAC was considered as the reference category, and logistic regression was used to estimate the relationship between prediabetes with HEI-215 and DTAC.

RESULTS

Mean age and body mass index of participants were 47.42 ± 15.98 years and 27.90 ± 4.96 kg/m2. Patients with prediabetes had lower DTAC scores when compared to controls (11.86 ± 5.77 and 17.81 ± 12.08, P = 0.01). There was a significant inverse association between the highest tertile of the DTAC score when compared with the lowest tertile in crude (OR = 0.11; 95% CI: 0.03-0.43), age-adjusted (OR = 0.13; 95% CI: 0.03-0.48), and fully adjusted (OR = 0.09; 95% CI: 0.02-0.53) models. In contrast, there was no difference between HEI-2015 in patients with prediabetes when compared to controls (74.41 ± 8.91 and 74.41 ± 9.35, respectively; P = 0.85). Correspondingly, no difference was observed between the highest tertile of the HEI-2015 score when compared with the lowest tertile in crude (OR = 1.23; 95% CI: 0.53-2.86), age-adjusted (OR = 1.17; 95% CI: 0.48-2.82), and fully adjusted (OR = 1.53; 95% CI: 0.56-4.16) models.

CONCLUSION

This study demonstrates a clear association between prediabetes with less DTAC, but not with HEI-2015.

Effects of purslane supplementation on C-reactive protein levels and biomarkers of oxidative stress as marks for metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

The antioxidant and antiinflammatory properties of purslane (Portulaca oleracea L.) are known in preclinical studies but further examination is needed to expand their potential into the clinical scenario. A systematic review and meta-analysis of randomized controlled trials were performed to elucidate the effects of purslane supplementation on C-reactive protein (CRP) levels and biomarkers of oxidative stress in metabolic syndrome, its related complications, and other diseases. PubMed/MEDLINE, Web of Science, SCOPUS, and Embase were the databases searched. Heterogeneity was examined using the I-squared (I² ) statistic, in which the source of heterogeneity was determined if the I² -value was >50%. After all the screening processes, 10 studies met the eligibility criteria and were analyzed. Following purslane supplementation, CRP levels decreased significantly (weighted mean difference [WMD]: -0.33 mg/dl, 95% confidence interval [CI]: -0.66, -0.004, p = .047) but with significant heterogeneity (I²  = 87.4%, p = .001). Purslane supplementation did not significantly change serum levels of malondialdehyde (MDA) (WMD: -0.353 μm/L; 95% CI: -0.920, 0.213; I²  = 50.7%), total antioxidant capacity (TAC) (WMD: 0.090 mm/L, 95% CI: -0.081, 0.262; I²  = 47.1%), and superoxide dismutase (SOD) (WMD: 6.54 U/ml, 95% CI: -22.150, 35.236; I²  = 70.7%). Thus, this meta-analysis showed a positive effect of purslane supplementation as a tool to decrease CRP levels, but not to MDA, TAC, and SOD levels.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively.

RESULTS

In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (β = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (β = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting.

CONCLUSIONS

Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

The effect of nigella sativa on biomarkers of inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials

Inflammation and oxidative stress are involved in the pathogenesis of a myriad of chronic disorders. This systematic review and meta-analysis was designed to determine the effects of Nigella Sativa (NS) seed and seed oil consumption on several biomarkers of inflammation and oxidative stress. The Scopus, Web of Science, and PubMed-MEDLINE databases were systematically searched until August 2019. The quality assessment and heterogeneity of the selected randomized clinical trials (RCTs) were measured using the Jadad checklist, and Q and I² tests, respectively. Finally, a total of 10 clinical RCTs were found to be eligible for this meta-analysis. The pooled findings showed that NS consumption significantly reduced serum high-sensitivity C-reactive protein (hs-CRP; WMD: -0.67, 95% CI: -1.29, -0.05, I²  = 95.7%), tumor necrosis factor-alpha (TNF-α; WMD: -2.29, 95% CI: -4.48, -0.11, I²  = 93%), and malondialdehyde (MDA; WMD: -1.18, 95% CI: -2.24, -0.12, I²  = 85.4%), and significantly increased total antioxidant capacity (TAC; WMD: 0.35, 95% CI: 0.10, 0.59, I²  = 77.1%), and superoxide dismutase (SOD; WMD: 66.30, 95% CI: 1.03, 131.57, I²  = 99.4%) levels. Overall, the results of this systematic review and meta-analysis imply that NS consumption may decrease inflammatory response and oxidative stress markers. PRACTICAL APPLICATIONS: Overall, the evidence supports the consumption of NS to reduce hs-CRP, TNF-α, and MDA, and to increase SOD and TAC levels. In addition, the subgroup analyses findings concluded that lower dosages of NS, longer durations of the intervention, and the use of NS seed oil may result in more effective action on inflammatory markers, but because of the limited number of trials, the results must be analyzed with caution, especially for the subgroup analysis. However, further prospective studies regarding the effect of NS consumption on biomarkers of inflammation and oxidative stress, with larger sample sizes, from various countries and longer follow-up periods, are required to confirm whether NS possesses veritable anti-inflammatory and antioxidant effects.

Low Serum Zinc Levels and Associated Risk Factors in Hospitalized Patients Receiving Oral or Enteral Nutrition: A Case-control Study

PURPOSE

To assess whether hospitalization and feeding strategy impact the risk of hypozincemia and associated risk factors.

METHODS

In this case-control study, serum zinc levels were compared between inpatients fed oral nutrition (ON) (n = 76) or enteral nutrition (EN) (n = 191) with outpatient controls (n = 1095).

FINDINGS

Zinc levels were significantly lower in inpatients receiving EN compared with those receiving ON (P = 0.001). Significant (P < 0.001) β-values of -11.16 and -17.58 for serum zinc concentrations were found for inpatients receiving ON or EN, respectively, compared with the outpatients. Hospitalization and old age were both independent predictors of zinc deficiency. More than 75% of patients >60 years of age fed EN had a zinc concentration <68.75 μg/dL. Low hemoglobin levels increased the risk of low zinc levels for inpatients receiving EN (P = 0.003) and ON (P = 0.026). Age (P < 0.001), noninvasive mechanical ventilatory support (P = 0.016), and critical care (P = 0.018) were risk factors for hypozincemia in patients receiving ON. Low iron levels were associated with hypozincemia (P = 0.001) in patients receiving EN.

IMPLICATIONS

Hospitalization and being >60 years of age were risk factors for zinc deficiency. Intensive care and noninvasive mechanical ventilatory support were risk factors for hypozincemia in hospitalized patients who were fed orally. Low hemoglobin levels increased the risk of low zinc concentrations for inpatients receiving EN and ON, and low iron levels were associated with hypozincemia only after EN.

Use of medicinal doses of zinc as a safe and efficient coadjutant in the treatment of male hypogonadism

Hypogonadism affects an extensive part of the male population, especially among the elderly. The quest for treatment regarding low levels of serum testosterone and male infertility has, therefore, worldwide relevance. Zinc has important biological actions insofar as the male reproductive physiology and endocrine system. In general, a common and safe recommendation for zinc in the treatment of male hypogonadism is 220 mg of zinc sulfate (equivalent to 50 mg of elemental zinc) twice a day, over one to four months. Additionally, it may be further required to extend, both the treatment, dose and daily fractionation of this mineral. Albeit medicinal doses of zinc may increase total testosterone and improve sperm count, the current body of evidence does not suggest broad recommendations regarding the use of zinc for all types of hypogonadism. In many cases, the use of zinc supplements is insufficient, with the use of surgery and drugs being required for an effective treatment.

The Impact of Low Advanced Glycation End Products Diet on Metabolic Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Several randomized clinical trials have investigated the effect of dietary advanced glycation end products (AGEs) on metabolic syndrome risk factors in adults. However, the results of these studies were conflicting. Therefore, our aim was to assess the effect of dietary AGEs on metabolic syndrome risk factors. We searched the PubMed-MEDLINE, Scopus, Cochrane Databases, Google Scholar, Web of Science, and Embase databases for papers published up to October 2019 that investigated the effect of dietary AGEs on metabolic syndrome risk factors. From the eligible trials, 13 articles were selected for inclusion in this systematic review and meta-analysis. The meta-analysis was performed using a random-effects model. Heterogeneity was determined by I2 statistics and Cochrane Q test. Pooled results from the random-effects model showed a significant reduction for insulin resistance [weighted mean difference (WMD): -1.204; 95% CI: -2.057, -0.358; P = 0.006], fasting insulin (WMD: -5.472 μU/mL; 95% CI: -9.718, -1.234 μU/mL; P = 0.011), total cholesterol (WMD: -5.486 mg/dL; 95% CI: -10.222, -0.747 mg/dL; P = 0.023), and LDL (WMD: -6.263 mg/dL; 95% CI: -11.659, -0.866 mg/dL; P = 0.023) in the low-AGEs groups compared with the high-AGEs groups. There were no changes in the other components of the metabolic syndrome. The results of this review suggest that a diet with a low AGEs content has beneficial effects on insulin resistance, fasting insulin, total cholesterol, and LDL. Moreover, following a diet low in AGEs may be a helpful strategy to decrease the burden of metabolic syndrome risk factors in adults and particularly in patients with diabetes.

Association of dietary fiber and depression symptom: A systematic review and meta-analysis of observational studies

BACKGROUND

A potential relationship between depression and the intake of dietary fiber has been hypothesized in several studies. However, no meta-analysis has been conducted so far to explore the association between these two variables. Hence, we designed the present meta-analysis to elucidate the relationship between the intake of dietary fiber and depression.

METHODS

A comprehensive search was performed using the PubMed/Medline, Scopus, Web of Science and Google Scholar databases to identify any relevant studies published from inception to October 2019. Observational studies (cross-sectional and case-control) were included in the analysis.

RESULTS

Pooled analysis from the random-effects model of four case-control studies revealed that the consumption of dietary fiber in patients with depression was significantly lower versus healthy controls (WMD: -1.41 mg/dl, 95 % CI: -2.32, -0.51, P = 0.002). No significant heterogeneity was demonstrated among the analyzed studies (I² = 4.0 %, P = 0.37). By pooling 5 effect sizes of cross-sectional studies (with a total of 97,023 subjects), we demonstrated that a higher dietary consumption of fiber was associated with significantly lower odds of depression (OR = 0.76; 95 % CI: 0.64, 0.90; P = 0.010), with a low heterogeneity seen among the retrieved studies (I² = 43.9 %; P = 0.12).

CONCLUSION

An increased intake of total dietary fiber is associated with lower odds of depression. Further studies are needed to evaluate the relationship between the different types of dietary fiber and depression.

Low-carbohydrate diets: Effects on metabolism and exercise - A comprehensive literature review

BACKGROUND & AIMS

Low-carbohydrate diets (LCD) have gained substantial attention in recent years for their potential in health promotion and treatment of diseases, but they remain controversial in nutrition guidelines and exercise performance. Herein, through a literature review, we discuss the current evidence base by considering management of LCD and potential coupling of these dietary regiments with physical exercise.

METHODS

We performed a comprehensive literature review with no date limits as a means of including seminal to current studies.

RESULTS

Reduction of CHO intake decreases muscle glycogen, yielding greater fat oxidation and associated metabolic benefits. LCD may promote fat mass loss and regulation of biochemical parameters, such as lipid and glycemic biomarkers. The therapeutic potential of LCD towards noncommunicable diseases, particularly obesity and its comorbidities, is therefore reasonable as a dietary candidate in this context. Potential benefits to this approach are linked to enhancement of mitochondrial gene expression and mitochondrial biogenesis. As such, LCD may be a feasible tool in a 'periodized nutrition' for athletes and within clinical scenarios. Long-term observational follow-up studies have demonstrated increased mortality and cardiovascular implications of LCD. However, harmful associations may depend on the food source (e.g., animal-based vs. plant-based foods).

CONCLUSION

LCD may decrease body mass, waist circumference, and improve fat and carbohydrate metabolism. When combined with exercise, LCD seems to be an effective strategy in regulating metabolic factors of cardiovascular diseases. Conversely, LCD may be associated with higher mortality and metabolic dysregulations if it contains large amounts of animal-based foods, particularly saturated fat.

The effects of dehydroepiandrosterone (DHEA) supplementation on body composition and blood pressure: A meta-analysis of randomized clinical trials

Dehydroepiandrosterone (DHEA) supplementation has been anecdotally considered as a tool to improve body composition and health status. We aimed to verify the impact of DHEA supplementation on traditional measurements of body composition and blood pressure (BP) due to their clinical applicability. A meta-analysis of randomized clinical trials was conducted based on the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Regarding anthropometric characteristics, DHEA supplementation did not change body weight (weighted mean difference (WMD): -0.16 kg, 95% CI: -1.02 to 0.70, p = 0.72) or body mass index (WMD: -0.18 kg/m², 95% CI: -0.48 to 0.12, p = 0.24), but increased lean body mass (WMD: 0.45 kg, 95% CI: 0.15 to 0.75, p = 0.004) and decreased fat mass (WMD: -0.85%, 95% CI: -1.18 to -0.51, p = 0.000), when compared to control groups. Neither systolic (WMD: 0.98 mm Hg, 95% CI: -2.31 to 4.29, p = 0.56) nor diastolic BP were significantly changed (WMD: -1.62 mm Hg, 95% CI: -5.49 to 2.24, p = 0.49). Our findings demonstrate that DHEA supplementation increased lean body mass and decreased fat mass, but debate persists when translating the results into clinical benefit. Lastly, DHEA supplementation had a neutral effect on BP.

Melatonin supplementation in the management of obesity and obesity-associated disorders: A review of physiological mechanisms and clinical applications

Despite the evolving advances in clinical approaches to obesity and its inherent comorbidities, the therapeutic challenge persists. Among several pharmacological tools already investigated, recent studies suggest that melatonin supplementation could be an efficient therapeutic approach in the context of obesity. In the present review, we have amalgamated the evidence so far available on physiological effects of melatonin supplementation in obesity therapies, addressing its effects upon neuroendocrine systems, cardiometabolic biomarkers and body composition. Most studies herein appraised employed melatonin supplementation at dosages ranging from 1 to 20 mg/day, and most studies followed up participants for periods from 3 weeks to 12 months. Overall, it was observed that melatonin plays an important role in glycaemic homeostasis, in addition to modulation of white adipose tissue activity and lipid metabolism, and mitochondrial activity. Additionally, melatonin increases brown adipose tissue volume and activity, and its antioxidant and anti-inflammatory properties have also been demonstrated. There appears to be a role for melatonin in adiposity reduction; however, several questions remain unanswered, for example melatonin baseline levels in obesity, and whether any seeming hypomelatonaemia or melatonin irresponsiveness could be clarifying factors. Supplementation dosage studies and more thorough clinical trials are needed to ascertain not only the relevance of such findings but also the efficacy of melatonin supplementation.