Effects of Calorie Restriction on Preserving Male Fertility Particularly in a State of Obesity.

PURPOSE OF REVIEW: Highlight the importance of exploring nutritional interventions that could be applied as alternative or supplementary therapeutic strategies to enhance men's fertility. RECENT FINDINGS: Lifestyle choices have prompted extensive discussions regarding its implications and applications as a complementary therapy. The growing concern over the decline in sperm quality underscores the urgency of investigating these alternative interventions. Calorie restriction (CR) has emerged as a promising strategy to improve male fertility. The efficacy of CR depends on factors like age, ethnicity and genetics. Clinical studies, such as CALERIE, have shown an improvement in serum testosterone level and sexual drive in men with or without obesity. Additionally, CR has been shown to positively impact sperm count and motility; however, its effects on sperm morphology and DNA fragmentation remain less clear, and the literature has shown discrepancies, mainly due to the nature of technically dependent assessment tools. The review advocates a personalized approach to CR, considering individual health profiles to maximize its benefits. It underscores the need for routine, accessible diagnostic techniques in male reproductive health. It suggests that future research should focus on personalized dietary interventions to improve male fertility and overall well-being in individuals with or without obesity and unravel CR's immediate and lasting effects on semen parameters in men without obesity.

RNA m6A modification regulates L1 retrotransposons in human spermatogonial stem cell differentiation in vitro and in vivo.

The maintenance of genome integrity in the germline is crucial for mammalian development. Long interspersed element type 1 (LINE-1, L1) is a mobile genetic element that makes up about 17% of the human genome and poses a threat to genome integrity. N6-methyl-adenosine (m6A) plays an essential role in regulating various biological processes. However, the function of m6A modification in L1 retrotransposons and human germline development remains largely unknown. Here we knocked out the m6A methyltransferase METTL3 or the m6A reader YTHDF2 in human embryonic stem cells (hESCs) and discovered that METTL3 and YTHDF2 are crucial for inducing human spermatogonial stem cells (hSSCs) from hESCs in vitro. The removal of METTL3 or YTHDF2 resulted in increased L1 retrotransposition and reduced the efficiency of SSC differentiation in vitro. Further analysis showed that YTHDF2 recognizes the METTL3-catalyzed m6A modification of L1 retrotransposons and degrades L1 mRNA through autophagy, thereby blocking L1 retrotransposition. Moreover, the study confirmed that m6A modification in human fetal germ cells promotes the degradation of L1 retrotransposon RNA, preventing the insertion of new L1 retrotransposons into the genome. Interestingly, L1 retrotransposon RNA was highly expressed while METTL3 was significantly downregulated in the seminal plasma of azoospermic patients with meiotic arrest compared to males with normal fertility. Additionally, we identified some potentially pathogenic variants in m6A-related genes in azoospermic men with meiotic arrest. In summary, our study suggests that m6A modification serves as a guardian of genome stability during human germline development and provides novel insights into the function and regulatory mechanisms of m6A modification in restricting L1 retrotransposition.

Effectiveness of Nutritional Therapies in Male Factor Infertility Treatment: A Systematic Review and Network Meta-analysis.

BACKGROUND: Nutritional therapies are effective alternative treatments for male infertility or subfertility. These are cost-effective and easily implementable, unlike other advanced invasive treatments. Even moderate improvements in sperm quality could improve spontaneous pregnancy. OBJECTIVE: We aimed to compare the effectiveness of all nutritional therapies in male infertility/subfertility treatment and ranked their efficacy based on type and etiology. We intend to aid clinicians with an evidence-based approach to affordable and safer initial infertility treatment for those who mainly do not wish to have other advanced invasive treatments or could not afford or have access to them. METHODS: We included 69 studies with 94 individual study arms identified from bibliographic databases and registries. We included studies in adult men with proven infertility or subfertility that investigated nutritional or dietary supplement therapies compared with control or placebo and at least reported on a sperm parameter. We undertook a network meta-analysis and performed a pairwise meta-analysis on all sperm parameter outcomes and meta-regression. No language or date restriction was imposed. A systematic article search was concluded on August 29, 2022. RESULTS: Our network meta-analysis is the first to compare all dietary interventions in a single analysis, sub-grouped by intervention type and type of infertility. L-Carnitine with micronutrients, antioxidants, and several traditional herbal supplements showed statistically and clinically significant improvement in sperm quality. Meta-regression identified that improvement in the sperm count, motility and morphology translated into increased pregnancy rates (p < 0.001; p < 0.001; p < 0.002, respectively). In particular, L-carnitine with micronutrient therapy (risk ratio [RR]: 3.60, 95% CI 1.86, 6.98, p = 0.0002), followed by zinc (RR 5.39, 95% CI 1.26, 23.04, p = 0.02), significantly improved pregnancy rates. Men with oligozoospermia (RR 4.89), followed by oligoasthenozoospermia (RR 4.20) and asthenoteratozoospermia (RR 3.53), showed a significant increase in pregnancy rates. CONCLUSION: We ranked nutritional therapies for their ability to improve sperm quality in men with infertility. Nutritional therapies, particularly L-carnitine alone or combined with micronutrients, significantly improved sperm parameters and pregnancy rates even under severe conditions. We believe these affordable solutions may be valuable for people without access to or who do not wish to undergo more invasive and costly fertility treatments.

The Role of Oxidative Stress and Inflammation in X-Link Adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is an inherited disease caused by a mutation in the ABCD1 gene encoding a peroxisomal transmembrane protein. It is characterized by the accumulation of very-long-chain fatty acids (VLCFAs) in body fluids and tissues, leading to progressive demyelination and adrenal insufficiency. ALD has various phenotypes, among which the most common and severe is childhood cerebral adrenoleukodystrophy (CCALD). The pathophysiological mechanisms of ALD remain unclear, but some in vitro/in vivo research showed that VLCFA could induce oxidative stress and inflammation, leading to damage. In addition, the evidence that oxidative stress and inflammation are increased in patients with X-ALD also proves that it is a potential mechanism of brain and adrenal damage. Therefore, normalizing the redox balance becomes a critical therapeutic target. This study focuses on the possible predictors of the severity and progression of X-ALD, the potential mechanisms of pathogenesis, and the promising targeted drugs involved in oxidative stress and inflammation.

Chronic Fructose Substitution for Glucose or Sucrose in Food or Beverages and Metabolic Outcomes: An Updated Systematic Review and Meta-Analysis.

Despite the publication of several of meta-analyses in recent years, the effects of fructose on human health remains a topic of debate. We previously undertook two meta-analyses on post-prandial and chronic responses to isoenergetic replacement of fructose for sucrose or glucose in food or beverages (Evans et al. 2017, AJCN 106:506-518 & 519-529). Here we report on the results of an updated search with a complete re-extraction of previously identified studies and a new and more detailed subgroup-analysis and meta-regression. We identified two studies that were published after our previous analyses, which slightly altered effect sizes and conclusions. Overall, the isoenergetic substitution of fructose for glucose resulted in a statistically significant but clinically irrelevant reduction in fasting blood glucose, insulin, and triglyceride concentrations. A subgroup analysis by diabetes status revealed much larger reductions in fasting blood glucose in people with impaired glucose tolerance and type 2 diabetes. However, each of these subgroups contained only a single study. In people with a healthy body mass index, fructose consumption was associated with statistically significant, but clinically irrelevant reductions in fasting blood glucose and fasting blood insulin. Meta-regression of the outcomes by a number of pre-identified and post-hoc covariates revealed some sources of heterogeneity, such as year of publication, age of the participants at baseline, and participants' sex. However, the small number of studies and the large number of potential covariates precluded detailed investigations of effect sizes in different subpopulations. For example, well-controlled, high quality studies in people with impaired glucose tolerance and type 2 diabetes are still lacking. Taken together, the available data suggest that chronic consumption of fructose is neither more beneficial, nor more harmful than equivalent doses of sucrose or glucose for glycemic and other metabolic outcomes.

Sperm-oocyte interplay: an overview of spermatozoon's role in oocyte activation and current perspectives in diagnosis and fertility treatment.

The fertilizing spermatozoon is a highly specialized cell that selects from millions along the female tract until the oocyte. The paternal components influence the oocyte activation during fertilization and are fundamental for normal embryo development; however, the sperm-oocyte interplay is in a continuous debate. This review aims to analyze the available scientific information related to the role of the male gamete in the oocyte activation during fertilization, the process of the interaction of sperm factors with oocyte machinery, and the implications of any alterations in this interplay, as well as the advances and limitations of the reproductive techniques and diagnostic tests. At present, both PLCζ and PAWP are the main candidates as oocyte activated factors during fertilization. While PLCζ mechanism is via IP3, how PAWP activates the oocyte still no clear, and these findings are important to study and treat fertilization failure due to oocyte activation, especially when one of the causes is the deficiency of PLCζ in the sperm. However, no diagnostic test has been developed to establish the amount of PLCζ, the protocol to treat this type of pathologies is broad, including treatment with ionophores, sperm selection improvement, and microinjection with PLCζ protein or RNA.

Implications of RNA Viruses in the Male Reproductive Tract: An Outlook on SARS-CoV-2.

Emerging viral infections continuously pose a threat to human wellbeing. Several RNA viruses have managed to establish access to the male reproductive tract and persist in human semen. The sexual transmission of the virus is of critical public concern. The epidemiological inferences are essential to understand its complexity, particularly the probability of viral transmission from asymptomatic patients or those in the incubation period or from the patient who was previously infected and now fully recovered. From the clinical perspective, negative impacts in the male reproductive tract associated with RNA virus infection have been described, including orchitis, epididymitis, impaired spermatogenesis, and a decrease in sperm quality, which can affect male fertility at different time intervals. The disruption of anatomical barriers due to inflammatory responses might enable the viral invasion into the testis, and the immune privilege status of testes might facilitate a sustained persistence of the virus in the semen. In this review, the current knowledge about other RNA viruses that affect male reproductive health provides the framework to discuss the impact of the SARS-CoV-2 pandemic. The molecular mechanisms, sexual transmission, and viral impacts for mumps, HIV, Zika, and Ebola viruses are explored. We discuss the currently available information on the impact of SARS-CoV-2 and its sequelae in the male reproductive tract, particularly regarding presence in semen, its impact on sexual organs, and sperm quality. To date, no sexual transmission of SARS-CoV-2 has been reported, whereas the identification of viral particles in semen remains conflicting. In the purview of the earlier conducted analyses, it is essential to investigate further the long-term health impacts of SARS-CoV-2 on the male reproductive tract.

Impaired spermatogenesis in COVID-19 patients.

BACKGROUND: The current study aimed to determine the impact of SARS-CoV-2 infection on male fertility. METHODS: This is a single-center, hospital-based observational study that included autopsied testicular and epididymal specimens of deceased COVID-19 male patients (n=6) and recruited recovering COVID-19 inpatients (n=23) with an equal number of age-matched controls, respectively. We performed histopathological examinations on testicular and epididymal specimens, and also performed TUNEL assay and immunohistochemistry. Whereas, we investigated the semen specimen for sperm parameters and immune factors. FINDINGS: Autopsied testicular and epididymal specimens of COVID-19 showed the presence of interstitial edema, congestion, red blood cell exudation in testes, and epididymides. Thinning of seminiferous tubules was observed. The number of apoptotic cells within seminiferous tubules was significantly higher in COVID-19 compared to control cases. It also showed an increased concentration of CD3+ and CD68+ in the interstitial cells of testicular tissue and the presence of IgG within seminiferous tubules. Semen from COVID-19 inpatients showed that 39.1% (n=9) of them have oligozoospermia, and 60.9% (n=14) showed a significant increase in leucocytes in semen. Decreased sperm concentration, and increased seminal levels of IL-6, TNF-α, and MCP-1 compared to control males were observed. INTERPRETATION: Impairment of spermatogenesis was observed in COVID-19 patients, which could be partially explained as a result of an elevated immune response in testis. Additionally, autoimmune orchitis occurred in some COVID-19 patients. Further research on the reversibility of impairment and developing treatment are warranted. FUNDING: This study was supported by Ministry of Science and Technology of China Plan, Hubei Science and Technology Plan, National Key Research and Development Program of China, HUST COVID-19 Rapid Response Call, China and National Natural Science Foundation of China; these funding bodies are public institutions, and they had no role in study conception, design, interpretation of results, and manuscript preparation.

Heat Stress and Pulsed Unfocused Ultrasound: The Viability of these Physical Approaches for Drug Delivery into Testicular Seminiferous Tubules.

AIM: To investigate the application of Scrotal Heat Stress (SHS) and Pulsed Unfocused Ultrasound (PuFUS) to explore Blood-Testis Barrier (BTB) permeability in adult mice. BACKGROUND: The BTB provides a stable microenvironment and a unique immune barrier for spermatogenesis. Meanwhile, it blocks macromolecular substances access, including therapeutic agents and antibodies, thereby it decreases the therapeutic or immunocontraception effects. OBJECTIVES: To determine the viability of these physical approaches in delivering macromolecular substances into seminiferous tubules. MATERIALS & METHODS: Mice were subjected to receive single SHS intervention at 39°C, 41°C, or 43°C for 30 min. Whereas, mice received the PuFUS intervention at 1.75w/cm2, 1.25w/cm2, and 2.5w/cm2 for 2 min, 5 min, and 10 min, respectively. The Biotin and macromolecular substances (IgG, IgM, and exosomes) were separately injected into the testicular interstitium at different times following SHS or PuFUS interventions, to observe their penetration through BTB into seminiferous tubules. RESULTS: As detected by Biotin tracer, the BTB opening started from day-2 following the SHS and lasted for more than three days, whereas the BTB opening started from 1.5h following PuFUS and lasted up to 24h. Apparent penetration of IgG, IgM, and exosomes into seminiferous tubules was observed after five days of the SHS at 43°C, but none at 39°C, or any conditions tested with PuFUS. CONCLUSION: The current results indicate that SHS at 43°C comparatively has the potential for delivering macromolecular substances into seminiferous tubules, whereas the PuFUS could be a novel, quick, and mild approach to open the BTB. These strategies might be useful for targeted drug delivery into testicular seminiferous tubules. However, further studies are warranted to validate our findings.

Potential risks of SARS-CoV-2 infection on reproductive health.

The outbreak of 2019 novel coronavirus disease (COVID-19) has become a major pandemic threat worldwide. Such a public health emergency can greatly impact various aspects of people's health and lives. This paper focuses on its potential risks for reproductive health, including the reproductive system and its functioning, as well as gamete and embryo development, which could be affected by the virus itself, drug treatments, chemical disinfectants and psychological effects related to panic during the COVID-19 outbreak.

The association of age-related differences in serum total testosterone and sex hormone-binding globulin levels with the prevalence of diabetes.

BACKGROUND: Age-related differences of sex hormones are traditionally considered detrimental to certain diseases particularly in middle-aged and elderly males, however, it is imprudent to conclude without elucidating the influences of other age-related pathophysiology apart from reproductive aging. We sought to examine serum testosterone and sex hormone-binding globulin (SHBG) levels from different decades of life and their associations with the prevalence of diabetes in each respective decade. MATERIALS AND METHODS: A total of 6296 males participated in this multicenter cross-sectional study, aged between 40-79 years. Information on diabetes and associated risk factors were obtained by questionnaires. Serum total testosterone (TT), SHBG and calculated free testosterone (fT) were determined. RESULTS: Age-related stable level of TT even with significantly lower level of fT did not result in a higher age-related odds of diabetes. Whereas, age-related higher SHBG level was associated with a lower age-related odds of diabetes [-5.88 % (p = 0.038), -14.28 % (p = 0.003) and -23.53 % (p = 0.001) for males aged 50-59, 60-69, 70-79 years, respectively]. Also, the combined age-related differences of TT and SHBG levels were found associated with a lower age-related odds of diabetes [-2.21 % (p = 0.040), -8.16 % (p = 0.025) and -14.37 % (p = 0.002) for males aged 50-59, 60-69, 70-79 years, respectively]. CONCLUSIONS: The differences in hormonal levels of each age group category showed a negative association with the prevalence of diabetes in middle-aged and elderly males, however, this association could be deterred in the presence of obesity.

Plasma vascular endothelial growth factor B is elevated in non-alcoholic fatty liver disease patients and associated with blood pressure and renal dysfunction.

Vascular endothelial growth factor B (VEGF-B) is a critical metabolic regulator in insulin resistance, and lipid distribution. We intended to ascertain the relationship between circulating VEGF-B and non-alcoholic fatty liver disease (NAFLD) in the general public. We recruited a total of 194 general participants for a routine physical health examination; of these, 84 participants were identified with NAFLD and 110 without NAFLD based on ultrasonographic findings. Homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI), HbA1c, liver function, kidney function, plasma VEGF-B levels and indexes of metabolic syndrome (blood pressure, fasting plasma glucose, fasting lipids) were evaluated. Plasma VEGF-B values were significantly higher in individuals with NAFLD compared to those without NAFLD (P = 0.022), and analysis of covariance confirmed this result. VEGF-B showed a positive correlation with γ-glutamyl transpeptidase (γ-GT) and HOMA-IR in univariate analysis (q = 0.242; P = 0.001; q =0.174; P = 0.019, respectively). Multiple linear regression analysis showed that γ-GT and ALT were independently correlated with VEGF-B even after adjusted for gender and age (q = 0.286; P = 0.01; q =0.237; P = 0.033, respectively). Moreover, plasma VEGF-B showed a powerful correlation with blood pressure and renal dysfunction. Plasma VEGF-B might be a new clinical variable related to NAFLD and could be a proper biomarker for the early detection of hypertension and renal dysfunction. However, further studies with large cohorts' size are warranted to validate our findings.

Suitability of APINCH high-risk medications use in diabetes mellitus.

High-risk medicines are those that carry a high risk of causing fatal or serious injury if used in error. The globally used Institute for Safe Medication Practices's list of high-risk medicines refers to the general population without taking into account special populations, such as diabetic. By means of the literature search, the current review identified several medicines that were previously not included, and have the potential to cause harm to diabetes patients when used inappropriately, including fluoroquinolones, targeted cancer therapies, and tramadol. Additionally, this review identified risks that the included medicines may carry for diabetes patients, such as interactions between warfarin and sulfonylureas that may cause severe hypoglycemia or potentiation of gastrointestinal side effects with co-administration of opioids and various hypoglycemics. The proposed inclusions and respective recommendations are to be taken into consideration in diabetes care and help with the creation of high-risk medicine lists adapted to diabetes patients on an individual hospital level.

Low-glycemic index diets as an intervention for diabetes: a systematic review and meta-analysis.

BACKGROUND: Low-glycemic index (GI) diets are thought to reduce postprandial glycemia, resulting in more stable blood glucose concentrations. OBJECTIVE: We hypothesized that low-GI diets would be superior to other diet types in lowering measures of blood glucose control in people with type 1 or type 2 diabetes, or impaired glucose tolerance. METHODS: We searched PubMed, the Cochrane Library, EMBASE, and clinical trials registries for published and unpublished studies up until 1 March, 2019. We included 54 randomized controlled trials in adults or children with impaired glucose tolerance, type 1 diabetes, or type 2 diabetes. Continuous data were synthesized using a random effects, inverse variance model, and presented as standardized mean differences with 95% CIs. RESULTS: Low-GI diets were effective at reducing glycated hemoglobin (HbA1c), fasting glucose, BMI, total cholesterol, and LDL, but had no effect on fasting insulin, HOMA-IR, HDL, triglycerides, or insulin requirements. The reduction in fasting glucose and HbA1c was inversely correlated with body weight. The greatest reduction in fasting blood glucose was seen in the studies of the longest duration. CONCLUSIONS: Low-GI diets may be useful for glycemic control and may reduce body weight in people with prediabetes or diabetes.

Serum triglycerides as a risk factor for cardiovascular diseases in type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies.

OBJECTIVE: The importance of triglycerides (TG) level as a risk factor for cardiovascular diseases (CVD) has been extensively investigated in the general population; however, their relationship in patients with type 2 diabetes mellitus (T2DM) is uncertain. We aimed to assess the association of TG with CVD in T2DM individuals. RESEARCH DESIGN AND METHODS: We searched bibliographic databases for studies published until June 2018, reporting on the relationship between TG and CVD in T2DM people. A random-effects model with inverse variance weighting was used to compute pooled estimates of the most fully adjusted risk ratios (RR) and corresponding 95% confidence intervals (CI) according to TG categories, unit TG, and logarithm (log) of TG for CVD. RESULTS: A total of 31 studies were included, involving 132,044 T2DM patients with 10,733 incident cardiovascular events. The pooled RR (95% CI) of CVD for an increase in baseline TG, log TG by 1-mmol/l and categorized in the highest vs. the lowest TG in T2DM were 1.06 (1.02, 1.09), 1.30 (1.18, 1.42) and 1.30 (1.16, 1.46), corresponding to a CVD risk increase of 6%, 30% and 30%, respectively. The pooled RR (95% CI) of CVD for per 1-mmol/L TG increment in eight studies and TG categories in three studies were 1.03 (0.98, 1.08) and 1.39 (0.92, 2.1) in T2DM patients adjusted for other lipids parameter, respectively. CONCLUSIONS: In T2DM patients, an elevated triglyceride level cannot serve as an independent marker for an increased risk of cardiovascular events, but still, the higher serum TG levels tend to be associated with increased risks of CVD.

In Silico Integration Approach Reveals Key MicroRNAs and Their Target Genes in Follicular Thyroid Carcinoma.

To better understand the molecular mechanism for the pathogenesis of follicular thyroid carcinoma (FTC), this study aimed at identifying key miRNAs and their target genes associated with FTC, as well as analyzing their interactions. Based on the gene microarray data GSE82208 and microRNA dataset GSE62054, the differentially expressed genes (DEGs) and microRNAs (DEMs) were obtained using R and SAM software. The common DEMs from R and SAM were fed to three different bioinformatic tools, TargetScan, miRDB, and miRTarBase, respectively, to predict their biological targets. With DEGs intersected with target genes of DEMs, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed through the DAVID database. Then a protein-protein interaction (PPI) network was constructed by STRING. Finally, the module analysis for PPI network was performed by MCODE and BiNGO. A total of nine DEMs were identified, and their function might work through regulating hub genes in the PPI network especially KIT and EGFR. KEGG analysis showed that intersection genes were enriched in the PI3K-Akt signaling pathway and microRNAs in cancer. In conclusion, the study of miRNA-mRNA network would offer molecular support for differential diagnosis between malignant FTC and benign FTA, providing new insights into the potential targets for follicular thyroid carcinoma diagnosis and treatment.

Evaluation of Serum microRNAs in Patients with Diabetic Kidney Disease: A Nested Case-Controlled Study and Bioinformatics Analysis.

BACKGROUND Diabetic kidney disease (DKD) can result in end-stage kidney disease and renal failure. This study aimed to examine the expression of serum microRNAs (miRNAs), miR-20a, miR-99b, miR-122-5p, and miR-486-5p, and to use bioinformatics data to investigate the pathways involved in DKD. MATERIAL AND METHODS Serum miRNAs were obtained from 25 healthy volunteers, 50 patients with non-complicated type 2 diabetes mellitus (T2DM), and 42 patients with T2DM and DKD. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of serum miRNAs. Specificity and sensitivity of the association between serum miRNAs in DKD were evaluated by analysis of the receiver operating characteristic (ROC) area under the curve (AUC). Serum miRNAs and clinical parameters of the patients were compared. Bioinformatics data analysis accessed the miRNA targets involved in the pathways related to the pathogenesis of DKD. RESULTS Serum levels of miR-99b and miR-122 significantly increased, and mir-20a and miR-486 decreased in the DKD group compared with healthy controls. Serum levels of miR-20a, miR-99b, miR-486-5p, and miR-122-5p were significantly correlated with albuminuria, estimated glomerular filtration rate (eGFR), blood glucose and lipid profiles. ROC curve analysis showed that diagnostic accuracy of serum levels of miR-99b for DKD was superior to miR-486-5p, miR-122-5p, and miR-20a, resulting in AUCs of 0.895, 0.853, 0.80, and 0.697, respectively. These four miRNAs regulate several genes affecting oxidative stress, inflammation, and apoptosis. CONCLUSIONS Serum miR-99b, miR-486-5p, miR-122-5p, and miR-20a were differentially expressed in patients with T2DM and DKD and should be evaluated further as potential biomarkers for DKD.

Impact of Diabetes Mellitus on Radiological Presentation of Pulmonary Tuberculosis in Otherwise Non-Immunocompromised Patients: A Systematic Review.

BACKGROUND: Studies on the influence of diabetes mellitus on the radiological presentation of pulmonary tuberculosis performed so far yielded inconsistent results. We aimed to summarize the relevant evidence on this topic systematically. METHODS: We systematically searched PubMed/MEDLINE (1980-2016) and the references of related articles (English-language reports) for observational studies that compared the radiological presentation of pulmonary tuberculosis in diabetes and non-diabetes patients. RESULTS: A total of fifteen studies that enrolled 2,020 diabetic patients and 5,280 controls were included in this systematic review. None of the included studies showed any significant difference in the upper lobe involvement and or in bilateral disease between diabetes and non-diabetes patients. However, lower lung field cavitary disease was found to be more frequent (relative risks ranging from 2.76, 95% CI 2.28-3.35 to 4.47, 95% CI 2.62-7.62) in patients with poor glycemic control (HbA1C >9%). Similarly, a significantly higher proportion of cavitary disease in diabetes patients was reported by 7 out of 15 studies, the meta-analysis of cavities of any size/site also showed the significantly higher risk of cavitary disease in diabetes patients (p-value = 0.0008). Three studies stratified the presence of cavities by diabetes control status, finding a higher proportion of cavities in uncontrolled diabetic patients (relative risks ranging from 1.85, 95%CI 1.34-2.55 to 3.59, 95%CI 2.53-5.11). One out of four studies found a significantly higher proportion of nodular infiltrations in diabetes versus non-diabetes patients. CONCLUSION: While there is no difference in localization of lung lesions between patients with diabetes and non-diabetes, our review found that the risk of cavitary disease is relatively higher in diabetes patients. It is essential for researchers to unify the criteria for diabetes diagnosis, patient selection, and radiographic severity and stratify the results by the potentially confounding factors.