Long-chain omega-3 polyunsaturated fatty acids and the risk of heart failure

The Optimal Dosage and Duration of ω-3 PUFA Supplementation in Heart Failure Management: Evidence from a Network Meta-Analysis

Heart failure is a progressive condition associated with a high mortality rate. Despite advancements in treatment, many patients continue to experience less-than-ideal outcomes. ω-3 (n-3) polyunsaturated fatty acids (PUFAs) have been studied as a potential supplementary therapy for heart failure, but the optimal dosage and duration of supplementation remain unclear. This network meta-analysis (NMA) aimed to assess the efficacy of various n-3 PUFA supplementation regimens in patients with heart failure, focusing on dose-dependent and time-dependent effects. We conducted a systematic search for randomized controlled trials (RCTs) on n-3 PUFA supplementation in heart failure till 13 September, 2024. The primary outcome was the change in heart function, specifically left ventricular ejection fraction. Secondary outcomes included changes in peak oxygen consumption (VO2), blood B-type natriuretic peptide concentrations, and quality of life. The safety analysis focused on dropout rates (i.e., patients leaving the study for any reason before completion) and all-cause mortality. A frequentist-based NMA was performed. This NMA, which included 14 RCTs with 9075 participants (mean age, 66.0 y; 23.3% female), found that high-dose n-3 PUFA supplementation (2000-4000 mg/d) over a duration of ≥1 y significantly improved left ventricular ejection fraction and peak VO2 compared with those of control groups. Lower doses and shorter treatment periods did not produce the same benefits. No significant differences were found in dropout rates or all-cause mortality between the n-3 PUFAs and control groups. Long-term, high-dose n-3 PUFA supplementation, particularly with a predominance of docosahexaenoic acid or eicosapentaenoic acid, enhances cardiac function in patients with heart failure without increasing risk of adverse events. Further well-designed RCTs with long treatment durations (i.e., >1 y) and stringent heart failure inclusion criteria are necessary to confirm these findings and reduce potential biases. This trial was registered at PROSPERO as CRD42024590476.

Association of Plasma Omega-3 Levels With Incident Heart Failure and Related Mortalities

OBJECTIVE

To investigate the association between plasma omega-3 levels and incident heart failure (HF) and to examine their relationship with total and cardiovascular (CV) mortality among patients with preexisting HF.

PATIENTS AND METHODS

The UK Biobank is an ongoing prospective cohort study of individuals recruited in the United Kingdom between April 1, 2007, and December 31. 2010. We used Cox proportional hazards models to predict incident HF in those without baseline HF and total and CV mortality in those with baseline HF, all as a function of baseline plasma omega-3 levels.

RESULTS

In participants without HF at baseline (n=271,794), a generally linear inverse association was observed between omega-3 levels and incident HF during a median follow-up of 13.7 years. The risk was 21% lower in the highest quintile of omega-3 compared with the lowest quintile (hazard ratio, 0.79; 95% CI, 0.74 to 0.84; P<.001) in multivariable models. In parallel models in participants with prevalent HF (n=1239), risk for all-cause and CV mortality were both reduced by approximately 50% comparing top to bottom omega-3 quintiles (hazard ratio, 0.53; 95% CI, 0.33 to 0.86; and hazard ratio, 0.50; 95% CI, 0.31 to 0.79, respectively; both P<.01).

CONCLUSION

Higher plasma levels of marine omega-3 fatty acids were associated with a lower incidence of HF. Furthermore, among patients with preexisting HF, higher omega-3 levels were associated with lower risks of all-cause mortality and CV mortality. These findings suggest that increasing plasma omega-3 levels, whether by diet or supplementation, could reduce both risk for development of HF and death in those with prevalent HF.

Association between fish consumption and mortality in the E3N French women's cohort

Western studies have shown a non-linear association between fish consumption and mortality, which might be explained by exposure to chemical contaminants. This study aims to explore the associations between fish consumption or omega-3 polyunsaturated fatty acids (n-3 PUFA) and mortality within the prospective E3N French cohort, and to investigate the role of dietary exposure to contaminants in these associations. In the E3N cohort composed of 72,585 women, we assessed fish consumption and n-3 PUFA intake through a food questionnaire sent in 1993. To estimate the dietary exposure to contaminants, we used the food contamination database of the second French total diet study. Cox proportional hazard models were used to estimate the association between fish, lean fish, fatty fish, and n-3 PUFA intake, with the risk of all-cause or cause-specific mortality. During the follow-up (1993-2014), 6,441 deaths were recorded. A U-shaped association was observed between fish consumption and all-cause mortality (Poverall_association = 0.017). A similar association was observed with lean fish consumption, while the non-linear association between fatty fish consumption or n-3 PUFA intake and all-cause mortality did not reach statistical significance. A non-linear association was observed between fish consumption and lung cancer mortality (Poverall_association = 0.005). A positive and linear association was observed between fatty fish consumption or n-3 PUFA intake and breast cancer mortality (HR [CI95%]: 1.07 [1.01-1.15] and 1.08 [1.01-1.15]). Our results remained unchanged when further adjusting on dietary exposure to contaminants. Our results showed a U-shaped association between fish consumption and all-cause mortality and suggest a notable role of lean fish consumption in this association, but no role of dietary exposure to contaminants. Further studies are needed to better clarify this U-shaped association and the different impacts of fatty and lean fish consumption on health.

The EAT-Lancet Diet Index, Plasma Proteins, and Risk of Heart Failure in a Population-Based Cohort

BACKGROUND

The landmark EAT-Lancet Commission proposed that a planetary health diet is comprised mainly of plant-based foods. However, studies examining whether this diet is associated with heart failure (HF) are currently lacking. In addition, the potential proteomics mechanism on the association between diet and HF warrants further elucidation.

OBJECTIVES

This study aims to both examine the association between the EAT-Lancet diet index and risk of HF and identify plasma proteins underlying such an association.

METHODS

This prospective cohort study included 23,260 participants. HF cases during the follow-up were identified through the Swedish national register. An EAT-Lancet diet index (score range: 0-42) was created to assess adherence to the EAT-Lancet reference diet. In a subcohort (n = 4,742), fasting plasma proteins were quantified.

RESULTS

During a median follow-up of 25.0 years, 1,768 incident HF cases were documented. After adjusting for sociodemographic, lifestyle, diabetes, hypertension, use of lipid-lowering drugs, and body mass index, the HR per 3-point increase of the EAT-Lancet diet index was 0.93 (95% CI: 0.88-0.97). This association was robust in several sensitivity analyses. Among the included 136 plasma proteins, a total of 8 proteins (AM, GDF15, IL-6, TIM, CTSD, CCL20, FS, and FUR) were both inversely associated with the EAT-Lancet diet index and positively associated with risk of HF; the overall proteomic score mediated 9.4% (95% CI: 2.2%-32.1%) of the association.

CONCLUSIONS

Higher adherence to the EAT-Lancet diet was associated with a lower risk of HF. The identified eight plasma proteins provide information on potential pathways mediating such an association.

Altered myocardial lipid regulation in junctophilin-2-associated familial cardiomyopathies

Myocardial lipid metabolism is critical to normal heart function, whereas altered lipid regulation has been linked to cardiac diseases including cardiomyopathies. Genetic variants in the JPH2 gene can cause hypertrophic cardiomyopathy (HCM) and, in some cases, dilated cardiomyopathy (DCM). In this study, we tested the hypothesis that JPH2 variants identified in patients with HCM and DCM, respectively, cause distinct alterations in myocardial lipid profiles. Echocardiography revealed clinically significant cardiac dysfunction in both knock-in mouse models of cardiomyopathy. Unbiased myocardial lipidomic analysis demonstrated significantly reduced levels of total unsaturated fatty acids, ceramides, and various phospholipids in both mice with HCM and DCM, suggesting a common metabolic alteration in both models. On the contrary, significantly increased di- and triglycerides, and decreased co-enzyme were only found in mice with HCM. Moreover, mice with DCM uniquely exhibited elevated levels of cholesterol ester. Further in-depth analysis revealed significantly altered metabolites from all the lipid classes with either similar or opposing trends in JPH2 mutant mice with HCM or DCM. Together, these studies revealed, for the first time, unique alterations in the cardiac lipid composition-including distinct increases in neutral lipids and decreases in polar membrane lipids-in mice with HCM and DCM were caused by distinct JPH2 variants. These studies may aid the development of novel biomarkers or therapeutics for these inherited disorders.

Marine omega-3 fatty acid supplementation and prevention of cardiovascular disease: update on the randomized trial evidence

To date, the VITamin D and OmegA-3 TriaL (VITAL) is the only large-scale randomized trial of marine omega-3 fatty acid (n-3 FA) supplementation for cardiovascular disease (CVD) prevention in a general population unselected for elevated cardiovascular risk. We review the findings of VITAL, as well as results from recent secondary prevention trials and updated meta-analyses of n-3 FA trials in the primary and secondary prevention of CVD. In VITAL, a nationwide sample of 25 871 US adults aged 50 and older, including 5106 African Americans, were randomized in a 2 × 2 factorial design to n-3 FAs (1 g/day; 1.2:1 ratio of eicosapentaenoic to docosahexaenoic acid) and vitamin D3 (2000 IU/day) for a median of 5.3 years. Compared with an olive oil placebo, the n-3 FA intervention did not significantly reduce the primary endpoint of major CVD events [composite of myocardial infarction (MI), stroke, and CVD mortality; hazard ratio (HR) = 0.92 (95% confidence interval 0.80-1.06)] but did significantly reduce total MI [HR = 0.72 (0.59-0.90)], percutaneous coronary intervention [HR = 0.78 (0.63-0.95)], fatal MI [HR = 0.50 (0.26-0.97)], and recurrent (but not first) hospitalization for heart failure [HR = 0.86 (0.74-0.998)]. The intervention neither decreased nor increased risk of atrial fibrillation. African Americans derived the greatest treatment benefit for MI and for recurrent hospitalization for heart failure (P interaction < 0.05 for both outcomes). Meta-analyses that include VITAL and high-risk or secondary prevention n-3 FA trials show coronary, but generally not stroke, risk reduction. More research is needed to determine which individuals may be most likely to derive net benefit. (VITAL clinicaltrials.gov identifier: NCT01169259).

Helicobacter pylori infection and risk of cardiovascular disease

BACKGROUND

Whether Helicobacter pylori (H. pylori) infection is associated with an increased risk of cardiovascular disease (CVD) remains controversial. This study aimed to investigate the association between H. pylori infection and the risk of CVD.

METHODS

Potentially related studies were searched in the electronic databases, including PubMed, EMBASE and Cochrane Library, from inception to 31 August 2022. Observational cohort studies that reported the multivariable-adjusted relative risks (RRs) for composite CVD, CHD, stroke, or all-cause mortality associated with H. pylori infection were included in the meta-analysis, using random-effects models.

RESULTS

Forty-one cohort studies with 230,288 participants were included. After a median follow-up duration of 6.3 years, H. pylori infection was associated with a mildly increased risk of composite CVD (RR 1.10, 95% CI 1.03, 1.18) and coronary heart disease (RR 1.10, 95% CI 1.02, 1.18) compared with those without H. pylori infection. No significant association was observed between H. pylori infection and risk of stroke (RR 1.08, 95% CI 0.94, 1.23) or all-cause mortality (RR 1.02, 95% CI 0.90, 1.16). Compared with cytotoxin-associated gene-A (CagA) negative H. pylori infection, the risk of CVD was significantly increased in patients with CagA positive H. pylori infection (RR 1.58, 95% CI 1.03, 2.41).

CONCLUSIONS

Helicobacter pylori infection is associated with a mildly increased risk of CVD. It may be of great public health and clinical significance to screen H. pylori infection in patients with a high risk of CVD.

n-3 PUFA poor seafood consumption is associated with higher risk of gout, whereas n-3 PUFA rich seafood is not: NHANES 2007–2016

Background and aims

Gout, the most prevalent inflammatory arthritis, has undesirable effects on the quality of life. Omega-3 polyunsaturated fatty acids (n-3 PUFA) has a strong link with anti-inflammatory impacts. However, whether the harmful effects of seafood in relation to gout may vary owing to different levels of n-3 PUFA in seafood is still unclear. It was the goal of this study to examine the relationship between n-3 PUFA poor/rich seafood consumption and gout.

Methods

Between 2007 and 2016, five NHANES cycles were performed, with 12,505 subjects having complete data for gout and two 24-h dietary intake interviews. The 24-h dietary recalls were utilized to evaluate dietary habits. Gout was defined based on questionnaires. Weighted logistic regression models were conducted to investigate the association between n-3 PUFA poor/rich seafood consumption and gout. Moreover, subgroup analysis was utilized to estimate the stability of results. Covariates including age, gender, race/ethnicity, income, education, body mass index, chronic kidney disease, diabetes mellitus, hypertension, smoking status, and drinking status were stratified in different models.

Results

In the fully adjusted model, each unit of increase of n-3 PUFA poor seafood intake was associated with an 8.7% increased risk of gout (OR = 1.087, 95% CI: 1.039, 1.138, P &lt; 0.001), whereas, no correlation was found between n-3 PUFA rich seafood consumption and gout. It also provided a proof-of-concept regarding the potential for n-3 PUFA rich seafood to counteract harmful effects of purines in relation to gout. A dose-response analysis showed that there was a non-linear relationship between n-3 PUFA rich seafood intake and the risk of gout in the female group.

Conclusion

Findings suggest that n-3 PUFA poor seafood consumption is associated with higher risk of gout, whereas n-3 PUFA rich seafood is not.

The association between heart failure and risk of fractures: Pool analysis comprising 260,410 participants

Background

HF and osteoporosis shared many common etiological risk factors. However, studies exploring whether patients with HF were associated with a higher risk of osteoporotic fracture resulted in inconsistent findings. This meta-analysis aimed to summarize the association between HF and the risk of incident fracture.

Methods

Following the Meta-analysis of Observational Studies in Epidemiology group recommendations, we searched multiple electronic databases (PubMed, Cochran Library, and EMBASE) for related studies from inception to April 30, 2021. Studies evaluating the risk of incident fracture in patients with HF compared with those without HF were included for analysis. The random-effects models were used to combine the estimated hazard ratios (HRs) of incident fracture associated with HF.

Results

We included 8 observational studies for meta-analysis. The sample size ranged from 5,613 to 87,748 participants, with a total of 260,410 participants included. The median follow-up duration was 5.0 years. Random-effects model analyses showed that compared with control groups, patients with HF were associated with a higher risk of all incident fractures (HR = 1.67, 95% CI = 1.30–2.16, P < 0.001) and hip fracture (HR = 2.20, 95% CI = 1.28–3.77, P < 0.001). The risk of all incident fractures was increased in all subgroup analyses according to age, sample size, sex, and follow-up duration.

Conclusions

Patients with HF were associated with a higher risk of incident fracture, as well as hip fracture.

Clinical significance of polyunsaturated fatty acids in the prevention of cardiovascular diseases

Cardiovascular diseases are one of the most important problems of modern medicine. They are associated with a large number of health care visits, hospitalizations and mortality. Prevention of atherosclerosis is one of the most effective strategies and should start as early as possible. Correction of lipid metabolism disorders is associated with definite clinical successes, both in primary prevention and in the prevention of complications of many cardiovascular diseases. A growing body of evidence suggests a multifaceted role for polyunsaturated fatty acids. They demonstrate a variety of functions in inflammation, both participating directly in a number of cellular processes and acting as a precursor for subsequent biosynthesis of lipid mediators. Extensive clinical data also support the importance of polyunsaturated fatty acids, but all questions have not been answered to date, indicating the need for further research.

Development of Prediction Model to Estimate the Risk of Heart Failure in Diabetes Mellitus

Background

Heart failure (HF) is a leading cause of mortality and disability in patients with diabetes mellitus (DM). The aim of the study is to predict the risk of HF incidence in patients with DM by developing a risk prediction model.

Methods

We constructed a regression model based on 270 inpatients with DM between February 2018 and January 2019. Binary logistic regression was applied to develop the final model incorporating the predictors selected by least absolute shrinkage and selection operator regression. The nomogram was estimated with an area under the receiver operator characteristic curve and calibration diagram and validated with the bootstrap method.

Results

Risk factors including age, coronary heart disease (CHD), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were incorporated in the final model as predictors. Age ≥ 61 years old, LDL, and CHD were risk factors for DM with HF, with odds ratios (ORs) of 32.84 (95% CI: 6.74, 253.99), 1.33 (95% CI: 1.06, 1.72), and 3.94 (95% CI: 1.43, 13.43), respectively. HDL was a protective factor with an OR of 0.11 (95% CI: 0.04, 0.28). The area under curve of the model was 0.863 (95% confidence interval, 0.812∼0.913). The plot of the calibration showed that there was a good consistency between predicted probability and actual probability. Harrell’s C-index of the nomogram was 0.845, and the model showed satisfactory calibration in the internal validation cohort.

Conclusion

The prediction nomogram we developed can estimate the possibility of HF in patients with DM according the predictor items.

Triglyceride-Glucose Index and Homeostasis Model Assessment-Insulin Resistance in Young Adulthood and Risk of Incident Congestive Heart Failure in Midlife: The Coronary Artery Risk Development in Young Adults Study

Objective

This study aimed to assess the association between triglyceride-glucose (TyG) index/homeostasis model assessment-insulin resistance (HOMA-IR) within young adults and congestive heart failure (CHF), and to explore whether TyG index can replace HOMA-IR as a surrogate marker for IR in predicting the risk of CHF.

Methods

A total of 4,992 participants between the ages of 18 and 30 years were enrolled from the Coronary Artery Risk Development in Young Adults (CARDIA) investigation [from 1985 to 1986 (year 0)]. A Cox proportional hazard regression analysis was conducted for assessing correlations between baseline TyG index/HOMA-IR and CHF events, together with the receiver operating characteristic (ROC) curve employed for scrutinizing TyG index/HOMA-IR and the risk of CHF.

Results

During the 31-year follow-up period, 64 (1.3%) of the 4,992 participants developed CHF. In multivariable Cox proportional hazards models, adjusted for confounding factors for CHF, an increased risk of CHF was associated with a per-unit increase in the TyG index [hazard ratio (HR) 2.8; 95% confidence interval (CI), 1.7–4.7] and HOMA-IR (HR 1.2; 95% CI, 1.1–1.3). A Kaplan–Meier curve analysis showed that participants in the TyG index and HOMA-IR index Q4 group had a higher risk of CHF than those in the Q1 group. The area under curve (AUC) for the TyG index and HOMA-IR consisted of 0.67 (95% CI, 0.6–0.742) and 0.675 (95% CI, 0.604–0.746), respectively. There were no significant differences between the TyG index and HOMA-IR for AUC (p = 0.986).

Conclusion

The higher TyG index and HOMA-IR are independent risk factors for CHF. The TyG index can replace HOMA-IR in young adulthood as a surrogate marker for IR to predict the risk of CHF.

Biomarkers of Oxidative Stress Tethered to Cardiovascular Diseases

Cardiovascular disease (CVD) is a broad term that incorporated a group of conditions that affect the blood vessels and the heart. CVD is a foremost cause of fatalities around the world. Multiple pathophysiological mechanisms are involved in CVD; however, oxidative stress plays a vital role in generating reactive oxygen species (ROS). Oxidative stress occurs when the concentration of oxidants exceeds the potency of antioxidants within the body while producing reactive nitrogen species (RNS). ROS generated by oxidative stress disrupts cell signaling, DNA damage, lipids, and proteins, thereby resulting in inflammation and apoptosis. Mitochondria is the primary source of ROS production within cells. Increased ROS production reduces nitric oxide (NO) bioavailability, which elevates vasoconstriction within the arteries and contributes to the development of hypertension. ROS production has also been linked to the development of atherosclerotic plaque. Antioxidants can decrease oxidative stress in the body; however, various therapeutic drugs have been designed to treat oxidative stress damage due to CVD. The present review provides a detailed narrative of the oxidative stress and ROS generation with a primary focus on the oxidative stress biomarker and its association with CVD. We have also discussed the complex relationship between inflammation and endothelial dysfunction in CVD as well as oxidative stress-induced obesity in CVD. Finally, we discussed the role of antioxidants in reducing oxidative stress in CVD.

Association Between Prognostic Nutritional Index and Prognosis in Patients With Heart Failure: A Meta-Analysis

Background

The prognostic nutritional index (PNI) has been proposed as a marker of malnutrition and associated with the prognosis of cardiovascular disease. However, whether PNI can serve as a potential biomarker for the prognosis of heart failure (HF) upon those established risk factors were still controversial. This meta-analysis aimed to generate comprehensive evidence on the prognostic value of PNI in patients with HF.

Methods

Multiple databases (PubMed, Embase, the Cochrane Library, and Google Scholar) were searched for related studies up to January 31, 2022. Observational studies accessed associations between PNI levels and the prognosis in patients with HF were included for meta-analysis. The hazard ratios (HRs) and 95% confidence intervals (CI) were calculated.

Results

Fourteen studies, comprising 19,605 patients with HF were included for meta-analysis. The median follow-up duration was 18.5 months. Compared with those with higher PNI (normal nutritional status), patients with HF with lower PNI (malnourished) were associated with a higher risk of all-cause mortality (HR 1.53, 95% CI 1.27–1.85) and composite major adverse cardiac outcomes (MACEs; HR 2.26, 95% CI 1.54–3.31) in the multivariable-adjusted model. Furthermore, when PNI was defined as per 1 increment as a continuous metric, higher PNI was associated with a decrease in all-cause mortality (per 1 increment of PNI: HR 0.94, 95% CI 0.88–0.96) and MACEs (per 1 increment of PNI: HR 0.97, 95% CI 0.95–0.98).

Conclusions

The PNI can serve as an easily calculated bedside “malnutrition-inflammation” biomarker in HF. Lower PNI was associated with a worse prognosis in patients with HF.

Association Between Dietary Fiber Intake and Heart Failure Among Adults: National Health and Nutrition Examination Survey 2009–2018

Objective

To explore the association between dietary fiber and heart failure (HF).

Methods

Data were collected from the 2009–2018 National Health and Nutrition Examination Survey. Dietary fiber intake data were obtained from two 24-h dietary recall interviews. Logistic regression and restricted cubic spline models were used to explore the association of dietary intakes of total, cereal, fruit, and vegetable fiber with HF prevalence.

Results

A total of 21869 adults were included in this study. After adjusting for multiple confounding factors, the odds ratios (OR) and 95% confidence intervals (CI) for HF was 0.49 (0.28 to 0.87, P for trend = 0.016) for the highest tertile versus lowest tertile of total fiber intake. Similar results were observed for cereal but not fruit and vegetable fiber intake. Dose-response analysis indicated that dietary intake of total and cereal fiber were inversely associated with HF in a linear manner.

Conclusion

Intakes of total and cereal fiber were inversely associated with HF in adults.

Knowledge Mapping of the Links Between the Gut Microbiota and Heart Failure: A Scientometric Investigation (2006–2021)

Background

There is considerable research value and extensive application perspectives to explore the link between gut microbiota and heart failure. The purpose of this study is to provide an overview of overall characteristics, evolutionary pathways, frontier research hotspots, and future trends in this field.

Methods

Research datasets were acquired from the Web of Science Core Collection (WoSCC) between January 1, 2006 and December 31, 2021. Three different analysis tools including one online platform, VOS viewer V1.6.17.0, and CiteSpace V5.8.R2 software were used in order to conduct collaboration network analysis, co-cited analysis, co-occurring analysis, and citation burst detection.

Results

A total of 873 publications in the WoSCC database met the requirement. The overall characteristics analysis showed that a steady growth trend in the number of publications and citations, with the predominant literature type being articles and the most frequent subject category being cardiac cardiovascular systems. The United States was the most prolific country and the center of national collaboration. Cleveland Clinic and Nathalie M. Delzenne provided the leading influence with publications, the cooperation between the institutes and authors were relatively weak. Moreover, gut microbiota, heart failure, risk factor, obesity, and inflammation were the keywords that appeared more frequently in the clustering analysis of reference co-citation and keyword co-occurrence. Burst detection analysis of top keywords showed that trimethylamine N-oxide (TMAO), bile acid, blood pressure, hypertension, and fermentation were the new research foci on the association between gut microbiota and heart failure. Strategies to improve gut microbiota hold promise as a new approach to treat heart failure.

Conclusion

The comprehensive bibliometric study indicates that the structured information may be helpful in understanding research trends in the link between gut microbiota and heart failure, and locating research hotspots and gaps in this domain, especially further advances in this field will lead to significant breakthroughs in the development of novel therapeutic tools for metabolic modulation of heart failure.

The Association Between Diabetes Mellitus and the Risk of Latent Tuberculosis Infection: A Systematic Review and Meta-Analysis

Background

The estimated global latent tuberculosis infection (LTBI) burden indicates a large reservoir of population at risk of developing active tuberculosis (TB). Previous studies suggested diabetes mellitus (DM) might associate with LTBI, though still controversial. We aimed to systematically assess the association between DM and LTBI.

Methods

We searched PubMed, Embase, Cochrane Library and Web of Science. Observational studies reporting the number of LTBI and non-LTBI individuals with and without DM were included. Random-effects or fixed-effects models were used to estimate the pooled effect by risk ratios (RRs) and odds ratios (ORs) and its 95% confidence interval (CI), using the original number of participants involved.

Results

20 studies involving 4,055,082 participants were included. The pooled effect showed a significant association between DM and LTBI (for cohort studies, RR = 1.62, 95% CI: 1.02-2.56; for cross-sectional studies, OR = 1.55, 95% CI: 1.30-1.84). The pooled OR was high in studies with healthcare workers (5.27, 95% CI: 1.52-8.20), refugees (2.88, 95% CI: 1.93-4.29), sample size of 1,000-5,000 (1.99, 95% CI: 1.49-2.66), and male participants accounted for less than 40% (2.28, 95% CI: 1.28-4.06). Prediabetes also associated with LTBI (OR = 1.36, 95% CI: 1.01-1.84).

Conclusion

The risk of LTBI was found to be a 60% increase in DM patients, compared with non-DM patients. LTBI screening among DM patients could be of vital importance. More studies are needed to explore appropriate strategies for targeted LTBI screening among DM patients.

Associations between rs3480 and rs16835198 gene polymorphisms of FNDC5 with type 2 diabetes mellitus susceptibility: a meta-analysis

BACKGROUND

FNDC5 is a novel and important player in energy regulation related to glucose metabolism and insulin levels. Thus, it may affect the incidence of type 2 diabetes mellitus (T2DM). Nevertheless, the association between FNDC5 single nucleotide polymorphisms (SNPs) and susceptibility to T2DM remains unclear. The aim of this meta-analysis was to explore whether the SNPs, rs3480 and rs16835198, are associated with the risk of T2DM.

METHODS

Studies published before February 1^st, 2022 were screened to identify the included studies. R software was also applied for calculation of odds ratio (OR), 95% confidence interval (95% CI), heterogeneity, and sensitivity analysis.

RESULTS

Seven studies for rs3480 (involving 5475 patients with T2DM and 4855 healthy controls) and five studies for rs16835198 (involving 4217 patients with T2DM and 4019 healthy controls) were included in this meta-analysis. The results revealed a statistically significant association of rs3480 with T2DM under homozygote (GG vs AA: OR = 1.76, 95% CI = 1.31-2.37, P = 0.0002, I² = 59%) genetic model. However, there was no statistically significant correlation between rs16835198 and susceptibility to T2DM under allelic (G vs T: OR = 1.33, 95% CI = 0.94-1.89, P = 0.11, I² = 84%), heterozygote (GT vs TT: OR = 1.17, 95% CI = 0.80-1.69, P = 0.42, I² = 71%), homozygote (GG vs TT: OR = 1.35, 95% CI = 0.95-1.94, P = 0.10, I² = 62%), recessive (GG+GT vs TT: OR = 1.25, 95% CI = 0.88-1.79, P = 0.22, I² = 72%), and dominant (GG vs GT+GG: OR = 1.20, 95% CI = 0.96-1.50, P = 0.11, I² = 46%) genetic models.

CONCLUSIONS

The present meta-analysis revealed that rs3480 in FNDC5 is significantly associated with susceptibility to T2DM, while rs16835198 does not show such an association.