Metabolic Syndrome and Risk of Lung Cancer: An Analysis of Korean National Health Insurance Corporation Database

Fatty liver index and development of lung cancer: a nationwide cohort study

BACKGROUND/AIMS

This study aimed to evaluate the impact of steatotic liver disease severity on the cumulative incidence of lung cancer utilizing data from the Korea National Health Insurance Service (NHIS).

METHODS

This study examined the risk of lung cancer in the general population in conjunction with the incidence of steatotic liver disease. The study population consisted of 3,261,438 individuals aged 20 years or older who underwent a general health examination in 2009.

RESULTS

Individuals with fatty liver index (FLI) of 30-59 exhibited a 1.08-fold increased risk of lung cancer (95% CI: 1.04-1.11), while FLI ≥ 60 was associated with a 1.22-fold elevated risk of lung cancer (95% CI: 1.17-1.28) compared to those with FLI < 30. The risk varied with smoking status; in current smokers, the adjusted HR for the FLI 30-59 group was 1.05 (95% CI: 1.00-1.10), while that in the FLI ≥ 60 group was 1.11 (95% CI: 1.04-1.18). In never- or past-smokers, the adjusted HR for the FLI 30-59 group was 1.10, and that for the FLI ≥ 60 group was 1.31. Subgroup analysis revealed an incidence rate of 1.06 per 1,000 person-years in the consistently high FLI group compared to 1.15 in those with improved FLI. Improving FLI over time was associated with a 0.93-fold decrease in lung cancer risk.

CONCLUSION

Our study demonstrated a correlational relationship between lung cancer incidence and the severity of steatotic liver disease as measured by FLI.

What is the role of nonalcoholic fatty liver disease in pulmonary carcinoma development?

This article summarizes the epidemiological characteristics and clinical manifestations of nonalcoholic fatty liver disease (NAFLD). The incidence of NAFLD has been increased dramatically and become the leading cause of chronic liver disease worldwide. In addition to its adverse outcomes of liver fibrosis, cirrhosis, and hepatocellular carcinoma, and related complications, NAFLD has recently been found to be associated with the high-risk extrahepatic carcinomas, such as various types of lung cancer (i.e., lung adenocarcinoma, squamous cell carcinoma, and small cell lung cancer). The presence of hepatic steatosis also predisposes lung cancer to liver metastasis, but has better response to immune checkpoint inhibitors. Whether other factors (i.e., gender, smoking, etc.) are associated with NAFLD and lung cancer remains controversial. We also comment on the reciprocal relationships between NAFLD and components of metabolic syndrome. Most metabolic syndrome components are suggested to facilitate lung cancer development via activating insulin/insulin-like growth factor axis. In addition, suppressed anti-tumor immunity and accelerated tumor progression could be attributed to the cell-specific metabolic reprogramming in condition of high-fat diet and related obesity. These findings may reveal the role of NAFLD in pulmonary carcinoma and help develop new treatment strategies for this disease.

Association between the C-reactive protein-albumin-lymphocyte index and metabolic syndrome: evidence from the 2003-2010 national health and nutrition examination survey

BACKGROUND

Metabolic syndrome (MetS) is a global public health problem that significantly impacts human health and quality of life. The relationship between MetS and the C-reactive protein-albumin-lymphocyte (CALLY) index is uncertain.

METHODS

This study analyzed the data of 7,534 individuals from the National Health and Nutrition Examination Survey cycles (2003-2010 cycles). Weighted logistic regression and weighted restricted cubic spline (RCS) curve analyses were used to identify the relationships between the CALLY index and MetS, as well as its components.

RESULTS

Of the 7,534 participants, 2,086 were diagnosed with MetS. The estimated prevalence of MetS decreased with an increase in the CALLY index (P < 0.001). Multivariable logistic regression analysis showed that the odds ratio of MetS was 0.25 (95% confidence interval 0.20-0.32, P < 0.001) in the highest CALLY index quartile compared with the lowest quartile after adjusting for confounding variables. The RCS curve analysis revealed non-linear relationships between the CALLY index and MetS or its components.

CONCLUSIONS

This study revealed an inverse relationship between the CALLY index and MetS risk. The CALLY index might be valuable for identifying individuals who are at a high risk of MetS.

CLINICAL TRIAL NUMBER

Not applicable.

The interplay of factors in metabolic syndrome: understanding its roots and complexity

Metabolic syndrome (MetS) is an indicator and diverse endocrine syndrome that combines different metabolic defects with clinical, physiological, biochemical, and metabolic factors. Obesity, visceral adiposity and abdominal obesity, dyslipidemia, insulin resistance (IR), elevated blood pressure, endothelial dysfunction, and acute or chronic inflammation are the risk factors associated with MetS. Abdominal obesity, a hallmark of MetS, highlights dysfunctional fat tissue and increased risk for cardiovascular disease and diabetes. Insulin, a vital peptide hormone, regulates glucose metabolism throughout the body. When cells become resistant to insulin's effects, it disrupts various molecular pathways, leading to IR. This condition is linked to a range of disorders, including obesity, diabetes, fatty liver disease, cardiovascular disease, and polycystic ovary syndrome. Atherogenic dyslipidemia is characterized by three key factors: high levels of small, low-dense lipoprotein (LDL) particles and triglycerides, alongside low levels of high-density lipoprotein (HDL), the "good" cholesterol. Such a combination is a major player in MetS, where IR is a driving force. Atherogenic dyslipidemia contributes significantly to the development of atherosclerosis, which can lead to cardiovascular disease. On top of that, genetic alteration and lifestyle factors such as diet and exercise influence the complexity and progression of MetS. To enhance our understanding and consciousness, it is essential to understand the fundamental pathogenesis of MetS. This review highlights current advancements in MetS research including the involvement of gut microbiome, epigenetic regulation, and metabolomic profiling for early detection of Mets. In addition, this review emphasized the epidemiology and fundamental pathogenesis of MetS, various risk factors, and their preventive measures. The goal of this effort is to deepen understanding of MetS and encourage further research to develop effective strategies for preventing and managing complex metabolic diseases.

The association between metabolic syndrome and lung cancer risk: a Mendelian randomization study

Metabolic syndrome (MetS) is closely linked to cancer development, with emerging evidence suggesting its association with pulmonary carcinoma. However, causal relationships remain unclear due to observational study limitations. Employing Mendelian randomization, we investigated the causal link between MetS and lung cancer (LC) susceptibility. The data utilized in this study were obtained from the publicly available genetic variation summary database. The causal relationship was assessed using the inverse variance weighting method (IVW), weighted median method, and MR-Egger regression. A sensitivity analysis was carried out to confirm the robustness of the findings. Furthermore, risk factor analyses were conducted to explore potential mediators. Utilizing various analyses, MetS demonstrated a significant positive association with LC (OR, 1.22; 95% CI, 1.09-1.37, p = 7.57 × 10- 4), lung squamous cell carcinoma (LUSC) (OR, 1.47; 95%, 1.23-1.75, p = 2.22 × 10- 5), and small cell lung cancer (SCLC) (OR, 1.76; 95% CI, 1.37-2.26, p = 8.20 × 10- 6) but not lung adenocarcinoma (LUAD) (OR, 1.08; 95% CI, 0.94-1.24, p = 0.28). Risk factor analyses indicated that smoking, alcohol, body mass index, education, and type 2 diabetes might mediate the association. This study genetically validates and reinforces the evidence of MetS increasing the incidence of LC, including both LUSC) and SCLC, especially among individuals with abdominal obesity. It provides valuable insights for the development of lung cancer prevention strategies and directions for future research.

The effect of metabolic syndrome on prognosis of diffuse large B-cell lymphoma

PURPOSE

Metabolic syndrome (MetS), characterized by insulin resistance, is closely associated with the prognosis of various cancer types, but has not been reported in diffuse large B-cell lymphoma (DLBCL). The aim of this study is to examine how other clinicopathological variables and the MetS influence the prognosis of DLBCL.

METHODS

Clinical and pathological data were collected from 319 patients with DLBCL who were admitted to our hospital between January 2012 and December 2020. The data accessible with SPSS 27.0 enables the utilization of various statistical methods for clinical data analysis, including independent sample t test and univariate and multivariate COX regression.

RESULTS

The presence of MetS was linked to both overall survival (OS) and progression-free survival (PFS), in addition to other clinicopathological characteristics as age, IPI score, rituximab usage, and Ki-67 expression level. This link with OS and PFS indicated a poor prognosis, as shown by survival analysis. Subsequent univariate analysis identified IPI score, Ki-67 expression level, tumor staging, rituximab usage, lactate dehydrogenase expression level, and the presence or absence of MetS as factors linked with OS and PFS. Furthermore, multivariate Cox regression analysis confirmed the independent risk factor status of IPI score, Ki-67 expression level, rituximab usage, and the presence of MetS in evaluating the prognosis of patients with DLBCL.

CONCLUSION

This study's findings indicate that patients with pre-treatment MetS had a poor prognosis, with relatively shorter OS and PFS compared to those without pre-treatment MetS. Furthermore, the presence of MetS, IPI score, Ki-67 expression level, and rituximab usage were identified as independent risk factors significantly affecting the prognosis of DLBCL.

The Association between Dyslipidemia and Pulmonary Diseases

Dyslipidemia is one of the most common diseases worldwide. As a component of metabolic syndrome, the prevalence and mechanism by which dyslipidemia promotes cardiovascular diseases has been well studied, although the relationship between pulmonary diseases is not well understood. Because the lung is a respiratory organ with a large surface area and is exposed to the environment outside the body, it continuously inhales various substances. As a result, pulmonary diseases have a vast diversity, including chronic inflammatory diseases, allergic diseases, cancers, and infectious diseases. Recently, growing evidence has suggested that dyslipidemia plays a role in the pathogenesis and prognosis of various pulmonary diseases. We herein review the current understanding of the relationship between dyslipidemia and pulmonary diseases, including chronic obstructive pulmonary diseases, asthma, and lung cancer, and infectious pulmonary diseases, including community-acquired pneumonia, tuberculosis, nontuberculous mycobacterial pulmonary disease, and COVID-19. In addition, we focus on recent evidence of the utility of statins, specifically 3-hydroxy-3-methylglutaryl-coA reductase inhibitors, in the prevention and treatment of the various pulmonary diseases described above.

Exploring the association between metabolic syndrome, its components and subsequent cancer incidence: A cohort study in Catalonia

BACKGROUND

Metabolic syndrome (MS) has emerged as a significant global health concern. The relationship between MS and the risk of cancer doesn't seem clear, whether examining by components or in combination. The objective of this study is to examine the relationship between MS, its components, and the overall risk of cancer, including the risk of 13 specific cancer types.

METHODS

We included 3,918,781 individuals aged 40 years or older sourced from the SIDIAP database between 2008 and 2017. Cox models were employed with MS components and their combinations. A subsample was created using a matched cohort (by age and sex). Incidence curves were computed to determine the time elapsed between the date of having 1-5 MS components and cancer incidence, compared to matched participants with no MS components, which showed that individuals who had one MS component experienced a greater incidence of cancer over 5 and 10 years than individuals with no MS, and the incidence rose with an increase in the number of MS components.

RESULTS

Individuals exposed to MS components were diagnosed with cancer earlier than those who were not exposed to them. In the Cox model, HDL (HR 1.46, 95% CI: 1.41-1.52) and Glycemia (HR 1.40, 95% CI: 1.37-1.44) were the individual combinations with the highest risk of overall cancer. In combinations with two components, the highest HR was HDL+Glycemia (HR 1.52, 95% CI: 1.45-1.59) and Glycemia+HBP (HR 1.48, 95% CI: 1.45-1.50). In combinations with three components, the highest HR was HDL+Glycemia+HBP (HR 1.58, 95% CI: 1.55-1.62).

CONCLUSION

In summary, having one or more MS components raises the risk of developing at least 11 cancer types and these risk differ according to type of component included. Some sex differences are also observed. Our findings suggest that implementing prevention measures aimed at specific MS components may lower the risk of various cancer types.

Perceptions and Proficiencies of Primary Care Physicians Treating Metabolic Syndrome: A Descriptive Survey-Based Study

INTRODUCTION

Metabolic syndrome (MetS) is a chronic condition that has been implicated in adverse public health outcomes worldwide, including in the United States. It has been linked to diseases such as type 2 diabetes and heart disease. Little is known about the perceptions and practices of primary care physicians (PCPs) regarding MetS. The only studies examining this research topic were conducted outside the United States. The aim of this study was to evaluate the MetS knowledge, proficiency, training, and practices of American PCPs, for the purpose of informing future physician education initiatives directed at MetS.

METHODS

This was a descriptive correlational design using a Likert-scale questionnaire. The survey was distributed to more than 4000 PCPs. The first 100 completed surveys were evaluated using descriptive statistical analyses.

RESULTS

Cumulative survey results revealed that most PCPs perceived themselves as knowledgeable on MetS, but only a minority demonstrated an understanding of leading-edge MetS protocols. Ninety-seven percent agreed that MetS is a condition of concern, but only 22% reported possessing sufficient time and resources to fully address MetS. Only half indicated that they had received training in MetS.

DISCUSSION

Overall results suggested that a lack of time, training, and resources may pose the greatest obstacles to optimal MetS care. Future studies should aim to identify the specific reasons why these barriers exist.

Association of Metabolic Syndrome With Risk of Lung Cancer: A Population-Based Prospective Cohort Study

BACKGROUND

Both the incidence of lung cancer and the prevalence of metabolic syndrome (MetS) have been increasing worldwide. The relationship between MetS and lung cancer remains controversial.

RESEARCH QUESTION

What is the risk of lung cancer associated with MetS and its components?

STUDY DESIGN AND METHODS

Multivariable Cox regression models were used to estimate the hazard ratio (HR) of MetS-related variables on lung cancer risk, both overall and by histologic subtype, in the UK Biobank. Stratified analyses were conducted by sex, tobacco use status, and use of medication. HR curves were used to test the nonlinear associations between the metabolic markers and the risk of lung cancer.

RESULTS

Of the 331,877 participants included in this study, a total of 77,173 participants had a diagnosis of MetS at enrollment. During a median follow-up of 10.9 years, lung cancer as the primary site developed in 2,425 participants. The HRs of MetS were 1.21 (95% CI, 1.09-1.33), 1.28 (95% CI, 1.10-1.50), and 1.16 (95% CI, 0.94-1.44) for the overall risk of lung cancer, adenocarcinoma, and squamous cell carcinoma, respectively. The HRs increased with the number of metabolic abnormalities from 1.11 to approximately 1.4 or 1.5 for those with one to five disorders. Positive association with lung cancer was observed for low high-density lipoprotein cholesterol (HDL-C), elevated waist circumference, and hyperglycemia. The relationship between MetS and lung cancer was modified by sex, with a stronger effect in female patients (P = .031). The risk of lung cancer resulting from MetS was elevated mainly among individuals who used tobacco, although the modification effect of tobacco use was not statistically significant. A nonlinear association was found between lung cancer and HDL-C, waist circumference, and glycated hemoglobin.

INTERPRETATION

The increased risk of lung cancer associated with MetS suggests the importance of taking metabolic status and markers into consideration for the primary prevention of lung cancer and the selection of high-risk populations for lung cancer screening.

Risk factors for early-onset lung cancer in Korea: analysis of a nationally representative population-based cohort

OBJECTIVES

We examined the associations of socioeconomic factors, health behaviors, and comorbidities with early-onset lung cancer.

METHODS

The study included 6,794,287 individuals aged 20-39 years who participated in a Korean national health check-up program from 2009 to 2012. During the follow-up period, 4,684 participants developed lung cancer. Multivariable Cox regression analysis was used to estimate the independent associations of potential risk factors with incident lung cancer.

RESULTS

Older age (multivariable hazard ratio [mHR], 1.13; 95% confidence interval [CI], 1.12 to 1.14) and female sex (mHR, 1.62; 95% CI, 1.49 to 1.75) were associated with increased lung cancer risk. Current smoking was also associated with elevated risk (<10 pack-years: mHR, 1.12; 95% CI, 1.01 to 1.24; ≥10 pack-years: mHR, 1.30; 95% CI, 1.18 to 1.45), but past smoking was not. Although mild alcohol consumption (<10 g/day) was associated with lower lung cancer risk (mHR, 0.92; 95% CI, 0.86 to 0.99), heavier alcohol consumption (≥10 g/day) was not. Higher income (highest vs. lowest quartile: mHR, 0.86; 95% CI, 0.78 to 0.94), physical activity for at least 1,500 metabolic equivalent of task-min/wk (vs. non-exercisers: mHR, 0.83; 95% CI, 0.69 to 0.99) and obesity (vs. normal weight: mHR, 0.89; 95% CI, 0.83 to 0.96) were associated with lower lung cancer risk, whereas metabolic syndrome was associated with increased risk (mHR, 1.13; 95% CI, 1.03 to 1.24).

CONCLUSIONS

In young adults, age, female sex, smoking, and metabolic syndrome were risk factors for early-onset lung cancer, while high income, physical activity, and obesity displayed protective effects.

Prediabetes and the risk of lung cancer incidence and mortality: A meta-analysis

AIMS/INTRODUCTION

There has been conflicting evidence regarding the role of prediabetes as a risk factor of lung cancer. A systemic review and meta-analysis was conducted to determine the relationship between prediabetes and lung cancer incidence and mortality in general adult populations.

MATERIALS AND METHODS

Observational studies relevant to the objective were found in Medline, Embase, Cochrane Library, and Web of Science. By incorporating potential heterogeneity into the model, a randomized-effects model was selected.

RESULTS

Ten cohort studies were included. People with prediabetes were associated with a mildly increased risk of lung cancer incidence compared with controls with normoglycemia (risk ratio [RR]: 1.09, 95% confidence interval [CI]: 1.01-1.18, P = 0.03; I2  = 79%), which was mainly observed in men rather than in women (RR: 1.07 vs 0.99, P for subgroup difference < 0.001). Prediabetes was related to a higher risk of lung cancer mortality (RR: 1.19, 95% CI: 1.02-1.39, P = 0.03; I2  = 52%), and the results were consistent in both men and women (P for subgroup difference = 0.67). The association between prediabetes and lung cancer incidence or mortality did not appear to be significantly affected by different definitions of prediabetes (P for subgroup difference = 0.27 and 0.37).

CONCLUSIONS

Prediabetes might be associated with a mildly increased risk of lung cancer incidence in men, but not in women. In addition, prediabetes may be related to a higher risk of lung cancer mortality in the adult population.

Effect of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and benzo[a]pyrene exposure on the development of metabolic syndrome in mice

AIM

The prevalence of metabolic syndrome (MetS), a cluster of serious medical conditions that raise the risk of lung cancer, has increased worldwide. Tobacco smoking (TS) potentially increases the risk of developing MetS. Despite the potential association of MetS with lung cancer, preclinical models that mimic human diseases, including TS-induced MetS, are limited. Here we evaluated the impact of exposure to tobacco smoke condensate (TSC) and two representative tobacco carcinogens, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNK) and benzo[a]pyrene (BaP), on MetS development in mice.

MATERIALS AND METHODS

FVB/N or C57BL/6 mice were exposed to vehicle, TSC, or NNK and BaP (NB) twice weekly for 5 months. The serum levels of total cholesterol (TCHO), triglycerides, high-density lipoprotein (HDL), blood glucose, and metabolites, along with glucose tolerance and body weight, were measured.

KEY FINDINGS

Compared with those of vehicle-treated mice, mice with TSC or NB exposure displayed major phenotypes associated with MetS, including increased serum levels of TCHO, triglycerides, and fasting and basal blood glucose and decreased glucose tolerance, and serum levels of HDL. These MetS-associated changes were found in both FVB/N and C57BL/6 mice that were susceptible or resistant to carcinogen-induced tumorigenesis, respectively, indicating that tumor formation is not involved in the TSC- or NB-mediated MetS. Moreover, oleic acid and palmitoleic acid, which are known to be associated with MetS, were significantly upregulated in the serum of TSC- or NB-treated mice compared with those in vehicle-treated mice.

SIGNIFICANCE

Both TSC and NB caused detrimental health problems, leading to the development of MetS in experimental mice.

The Impact of Metabolic Syndrome Risk Factors on Lung Function Impairment: Cross-Sectional Study

BACKGROUND

Metabolic syndrome (MetS) is a constellation of risk factors increasingly present in the world's population. People with this syndrome are at an increased risk of cardiovascular disease and type 2 diabetes mellitus. Moreover, evidence has shown that it affects different organs. MetS and its risk factors are independently associated with impaired lung function, which can be quantified through spirometric variables.

OBJECTIVE

This study aims to determine whether a high number of MetS criteria is associated with increased lung function decline.

METHODS

We conducted a descriptive cross-sectional study with a random sample of 1980 workers. Workers with acute respiratory pathology (eg, influenza), chronic respiratory pathology (eg, chronic bronchitis), or exposure to substances harmful to the lungs (eg, organic and inorganic dust) were not included. MetS was established based on harmonized criteria, and lung function was assessed according to spirometric variables. On the basis of these, classification into restrictive lung disease (RLD), obstructive lung disease, and mixed lung disease (MLD) was performed. In addition, the association between MetS and lung function was established based on analysis of covariance, linear trend analysis, and multiple linear regression.

RESULTS

MetS was associated with worse lung function according to all the spirometric parameters analyzed (percentage of predicted forced expiratory volume in 1 second: mean 83, SD 13.8 vs mean 89.2, SD 12.8; P<.001 and percentage of predicted forced vital capacity: mean 85.9, SD 11.6 vs mean 92, SD 11.3; P<.001). Moreover, those diagnosed with MetS had a higher prevalence of lung dysfunction (41% vs 21.9%; P<.001), RLD (23.4% vs 11.2%; P<.001), and MLD (7.3% vs 2.2%; P<.001). Furthermore, an increasing number of MetS criteria was associated with a greater impairment of pulmonary mechanics (P<.001). Similarly, with an increasing number of MetS criteria, there was a significant linear trend (P<.001) in the growth of the prevalence ratio of RLD (0 criteria: 1, 1: 1.46, 2: 1.52, 3: 2.53, 4: 2.97, and 5: 5.34) and MLD (0 criteria: 1, 1: 2.68, 2: 6.18, 3: 9.69, and 4: 11.37). Regression analysis showed that the alteration of all MetS risk factors, adjusted for various explanatory variables, was significantly associated with a worsening of spirometric parameters, except for forced expiratory volume in 1 second/forced vital capacity.

CONCLUSIONS

The findings have shown that an increase in cardiometabolic risk factors is associated with a more significant worsening of spirometric variables and a higher prevalence of RLD and MLD. As spirometry could be a crucial tool for monitoring patients at risk of developing chronic pathologies, we conclude that this inexpensive and easily accessible test could help detect changes in lung function in patients with cardiometabolic disorders. This highlights the need to consider the importance of cardiometabolic health in lung function when formulating public health policies.

Association of Metabolic Syndrome Components and Nutritional Status with Kidney Cancer in Young Adult Population: A Nationwide Population-Based Cohort Study in Korea

The aim of this study was to determine the association of metabolic syndrome (MetS) with kidney cancer and the impact of age and gender on such an association. Using the Korean National Health Insurance Service database, 9,932,670 subjects who had check-ups in 2009 were followed up until the diagnosis of kidney cancer or death or until 2019. Kidney cancer was significantly associated with MetS (HR 1.56). This association was higher in the younger age group (HR: 1.82, 1.5, and 1.37 in 20-39 years, 40-64 years, and ≥65 years, respectively). In terms of the association of kidney cancer with obesity and central obesity, young-aged males showed higher HR for kidney cancer than old-aged ones (HR of obesity: 1.96, 1.52, and 1.25; HR of central obesity: 1.94, 1.53, and 1.3 in 20-39 years, 40-64 years, ≥65 years, respectively), while young-aged females showed lower HR. Kidney cancer was associated with obesity and MetS. The association was higher in younger populations than in older ones. Regarding gender, MetS, obesity, and central obesity showed higher associations with kidney cancer in younger aged male population, while there was no significant difference in such associations according to age in the female population.

Synergism between the metabolic syndrome components and cancer incidence: results from a prospective nested case-control study based on the China Health and Retirement Longitudinal Study (CHARLS)

OBJECTIVES

Synergism between the metabolic syndrome (MetSyn) components and cancer incidence still remains inconclusive. We aimed to investigate the unique or joint role of MetSyn components in cancer onset.

DESIGN

We conducted a prospective nested case-control study based on the China Health and Retirement Longitudinal Study.

SETTING

An ongoing national representative longitudinal study included follow-up survey of people aged 45 years and older and their partners living in private households in China.

PARTICIPANTS

There were 17 708 individuals included at baseline. A total of 306 incident cancers was identified during the follow-up. For every case, we used incidence-density sampling to match three concurrent cancer-free controls by age, sex, and both duration and calendar time of follow-up. Exposure of interest was any MetSyn diagnosis at baseline.

RESULTS

We observed elevation in cancer risk associated with MetSyn in a significant way when the number of MetSyn components was over three (OR: 1.88; 95% CI: 1.19 to 2.97), or when components contained any of elevated triglycerides (OR: 1.61; 95% CI: 1.05 to 2.48), reduced high-density lipoprotein (HDL) cholesterol (OR: 2.33; 95% CI: 1.40 to 3.86) or elevated blood pressure (OR: 1.65; 95% CI: 1.04 to 2.59) after consistent multiple adjustments in different models. The highest cancer risk was in the female reproductive system and breast cancer (OR: 4.22; 95% CI: 1.62 to 10.95) followed by digestive system (OR: 1.67; 95% CI: 1.11 to 2.53). Sensitivity analyses showed similar results after first follow-up was excluded. However, any unique MetSyn component was not associated with increased cancer risk. Interestingly, the reduced HDL was observed to be widely associated with over twofold increased risk of cancer, only when together with other MetSyn components.

CONCLUSION

MetSyn components, in a collaborative manner rather than its unique component, were associated with elevated cancer risk. Not only obesity but even subtle metabolic disturbances may give rise to cancer.

Metabolic Obesity Phenotypes and Risk of Lung Cancer: A Prospective Cohort Study of 450,482 UK Biobank Participants

(1) Background: The association between metabolic obesity phenotypes and incident lung cancer (LC) remains unclear. (2) Methods: Based on the combination of baseline BMI categories and metabolic health status, participants were categorized into eight groups: metabolically healthy underweight (MHUW), metabolically unhealthy underweight (MUUW), metabolically healthy normal (MHN), metabolically unhealthy normal (MUN), metabolically healthy overweight (MHOW), metabolically unhealthy overweight (MUOW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). The Cox proportional hazards model and Mendelian randomization (MR) were applied to assess the association between metabolic obesity phenotypes with LC risk. (3) Results: During a median follow-up of 9.1 years, 3654 incident LC patients were confirmed among 450,482 individuals. Compared with participants with MHN, those with MUUW had higher rates of incident LC (hazard ratio (HR) = 3.24, 95% confidence interval (CI) = 1.33-7.87, p = 0.009). MHO and MHOW individuals had a 24% and 18% lower risk of developing LC, respectively (MHO: HR = 0.76, 95% CI = 0.61-0.95, p = 0.02; MHO: HR = 0.82, 95% CI = 0.70-0.96, p = 0.02). No genetic association of metabolic obesity phenotypes and LC risk was observed in MR analysis. (4) Conclusions: In this prospective cohort study, individuals with MHOW and MHO phenotypes were at a lower risk and MUUW were at a higher risk of LC. However, MR failed to reveal any evidence that metabolic obesity phenotypes would be associated with a higher risk of LC.

Temporal changes in serum uric acid and risk for metabolic syndrome: a longitudinal cohort study

BACKGROUND

Studies suggested elevated serum uric acid (SUA) levels are associated with metabolic syndrome (MetS). However, it remains unclear whether baseline SUA and temporal changes predict MetS. The study aimed to investigate the association of baseline SUA and its temporal longitudinal changes with subsequent risk of MetS.

METHODS

We conducted a retrospective longitudinal cohort study among 44,176 healthy participants aged 18 years and older without MetS at enrollment. The baseline levels and longitudinal changes of SUA were categorized by gender-specific quintiles. Participants were followed to identify newly developed MetS. We employed Cox model to investigate the relationship between SUA and MetS in men and women separately.

RESULTS

During a median follow-up of 2.4 years, 5461 (12.36%) participants developed MetS. After adjustment of demographic, major clinical factors, a higher level of baseline SUA was associated with a significant higher risk of MetS. The corresponding HRs (95% CIs) comparing participants at extreme quintiles were 2.59 (2.32, 2.88) in men and 2.87 (2.41, 3.43) in women. Larger longitudinal absolute increase in SUA was also related to an increases risk of MetS (top vs bottom quintile, 1.70 [1.53, 1.89] in men and 1.94 [1.65, 2.28] in women), regardless the level of baseline SUA. Similarly, the HRs about SUA longitudinal percentage changes were 1.74 (1.56, 1.94) in men and 2.01 (1.69, 2.39) in women, respectively. Moreover, we observed the highest risk of MetS among participants with both higher baseline SUA and larger longitudinal increase in SUA.

CONCLUSION

Higher baseline SUA and larger temporal increase in SUA independently predicted risk of MetS, highlighting the importance of longitudinal SUA monitoring and management for primary prevention of MetS in the general population.

Estimates of incidence, prevalence, mortality, and disability-adjusted life years of lung cancer in Iran, 1990-2019: A systematic analysis from the global burden of disease study 2019

BACKGROUND

Lung cancer is one of the leading cancers, with a high burden worldwide. As a developing country, Iran is facing with population growth, widespread tobacco use, demographic and epidemiologic changes, and environmental exposures, which lead to cancers becoming a severe concern of public health in Iran. We aimed to examine the burden of lung cancer and its risk factors in Iran.

METHODS

We utilized the Global Burden of Disease 2019 data and analyzed the total burden of the lung cancer and seven related risk factors by sex, age at national and sub-national levels from 1990 to 2019.

RESULTS

The lung cancer age-standardized death rate increased from 11.8 (95% Uncertainty Interval: 9.7-14.4) to 12.9 (11.9-13.9) per 100,000 between 1990 and 2019. This increase was among women from 5 (4.2-7.1) to 8 (7.2-8.8) per 100,000; in contrast, there was a decline among men from 18.5 (14.8-22.6) to 17.8 (16.2-19.4) per 100,000. The burden of lung cancer is concentrated in the advanced age groups. Smoking with 53.5% of total attributable deaths (51.0%-55.9%) was the leading risk factor. At the provincial level, there was a wide range between the lowest and highest, from 8.3 (7.0-10.0) to 19.1 (16.4-22.0) per 100,000 population in the incidence rate and from 8.7 (7.3-10.3) to 20.6 (17.7-24.0) per 100,000 population in mortality rate, respectively in Tehran and West Azerbaijan provinces in 2019.

CONCLUSION

The increasing trend of lung cancer burden among the entire Iranian population, the inter-provincial disparities, and the significant rise in burden of this cancer in women necessitate the urgent implementation and development of policies to prevent and manage lung cancer burden and strategies to reduce exposure to risk factors.

Association between metabolic syndrome and 13 types of cancer in Catalonia: A matched case-control study

Background

Metabolic syndrome (MS) is the simultaneous occurrence of a cluster of predefined cardiovascular risk factors. Although individual MS components are associated with increased risk of cancer, it is still unclear whether the association between MS and cancer differs from the association between individual MS components and cancer. The aim of this matched case-control study was to estimate the association of 13 types of cancer with (1) MS and (2) the diagnosis of 0, 1 or 2 individual MS components.

Methods

Cases included 183,248 patients ≥40 years from the SIDIAP database with incident cancer diagnosed between January 2008-December 2017. Each case was matched to four controls by inclusion date, sex and age. Adjusted conditional logistic regression models were used to evaluate the association between MS and cancer risk, comparing the effect of global MS versus having one or two individual components of MS.

Results

MS was associated with an increased risk of the following cancers: colorectal (OR: 1.28, 95%CI: 1.23–1.32), liver (OR: 1.93, 95%CI: 1.74–2.14), pancreas (OR: 1.79, 95%CI: 1.63–1.98), post-menopausal breast (OR: 1.10, 95%CI: 1.06–1.15), pre-menopausal endometrial (OR: 2.14, 95%CI: 1.74–2.65), post-menopausal endometrial (OR: 2.46, 95%CI: 2.20–2.74), bladder (OR: 1.41, 95%CI: 1.34–1.48), kidney (OR: 1.84, 95%CI: 1.69–2.00), non-Hodgkin lymphoma (OR: 1.23, 95%CI: 1.10–1.38), leukaemia (OR: 1.42, 95%CI: 1.31–1.54), lung (OR: 1.11, 95%CI: 1.05–1.16) and thyroid (OR: 1.71, 95%CI: 1.50–1.95). Except for prostate, pre-menopause breast cancer and Hodgkin and non-Hodgkin lymphoma, MS is associated with a higher risk of cancer than 1 or 2 individual MS components. Estimates were significantly higher in men than in women for colorectal and lung cancer, and in smokers than in non-smokers for lung cancer.

Conclusion

MS is associated with a higher risk of developing 11 types of common cancer, with a positive correlation between number of MS components and risk of cancer.

Impaired Lung Function and Lung Cancer Incidence: A Nationwide Population-Based Cohort Study

Background: It is unclear whether the presence of minimal lung function impairment is an independent risk factor for the development of lung cancer in general populations. Methods: We conducted a population-based cohort study using nationally representative data from the Korean National Health and Nutrition Examination Survey and the Korean National Health Insurance Service. Results: Of 20,553 participants, 169 were diagnosed with lung cancer during follow-up (median, 6.5 years). Participants with obstructive lung function impairment had increased risk of lung cancer (aHR: 2.51; 95% CI: 1.729–3.629) compared with those with normal lung function. The lower was the quartile or decile of forced expiratory volume in one second (FEV1) or the FEV1/forced vital capacity (FVC) ratio, the significantly higher was the incidence rate of lung cancer (p for trend < 0.0001). With FEV1 values in the lowest quartile (Q4), the incidence of lung cancer was significantly increased regardless of FVC (FEV1 Q4 and FVC values in the higher three quartiles Q1–3: aHR 1.754; 95% CI 1.084–2.847, FEV1 Q4 and FVC Q4: aHR 1.889; 95% CI 1.331–2.681). Conclusion: Our findings suggest that minimal lung function impairment, as expressed by lower FEV1 or FEV1/FVC value, may be associated with increased risk of lung cancer

The Obesity Paradox in Lung Cancer: Associations With Body Size Versus Body Shape

Background

The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC.

Methods

In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test.

Results

During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91–0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01–1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09–1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05–1.30) were positively and linearly associated with the risk of lung cancer.

Conclusions

Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms.