Metabolic Syndrome and Colorectal Cancer Risk: Results of Propensity Score-Based Analyses in a Community-Based Cohort Study

Genetic prediction of the relationship between metabolic syndrome and colorectal cancer risk: a Mendelian randomization study

BACKGROUND

Despite a growing body of observational studies indicating a potential link between metabolic syndrome and colorectal cancer, a definitive causal relationship has yet to be established. This study aimed to elucidate the causal relationship between metabolic syndrome and colorectal cancer through Mendelian randomization.

METHODS

We screened for instrumental variables associated with metabolic syndrome and its diagnostic components and with colorectal cancer through the use of a genome-wide association study database, and conducted a preliminary Mendelian randomization analysis. To corroborate the dependability of our conclusions, an additional dataset was used for replication analysis in a Mendelian randomization method, which was further integrated with a meta-analysis.

RESULTS

Preliminary analysis using the inverse variance weighted method revealed positive correlations between metabolic syndrome (OR [95% CI] = 1.37[1.15-1.63], P = 5.02 × 10-4) and waist circumference (OR [95% CI] = 1.39[1.21-1.61], P = 7.38 × 10-6) and the risk of colorectal cancer. Replication analysis also revealed the same results: metabolic syndrome (OR [95% CI] = 1.24[1.02-1.51], P = 0.030) and waist circumference (OR [95% CI] = 1.23[1.05-1.45], P = 0.013). The meta-analysis results further confirmed the associations between metabolic syndrome (OR [95% CI] = 1.31[1.15-1.49], P < 0.001) and waist circumference (OR [95% CI] = 1.32[1.18-1.47], P < 0.001) and colorectal cancer.

CONCLUSION

Our study indicated that metabolic syndrome increases the risk of CRC, particularly in patients with abdominal obesity.

Association between metabolic syndrome severity score and cardiovascular disease: results from a longitudinal cohort study on Chinese adults

Objective

This study aimed to quantify the severity of metabolic syndrome(MetS) and investigate its association with cardiovascular disease(CVD) risk on Chinese adults.

Methods

13,500 participants from the Zhejiang Adult Chronic Disease Study were followed up between 2010 and 2021. A continuous MetS severity score derived from the five components of MetS was used to quantify MetS severity, and the association between MetS severity and the risk of incident CVD was assessed using Cox proportional hazard and restricted cubic spline regression.

Results

Both the presence and severity of MetS were strongly associated with CVD risk. MetS was related to an increased risk of CVD (hazard ratio(HR):1.700, 95% confidence interval(CI): 1.380-2.094). Compared with the hazard ratio for CVD in the lowest quartile of the MetS severity score, that in the second, third, and highest quartiles were 1.812 (1.329-2.470), 1.746 (1.265-2.410), and 2.817 (2.015-3.938), respectively. A linear and positive dose-response relationship was observed between the MetS severity and CVD risk (P for non-linearity = 0.437). Similar results were found in various sensitivity analyses.

Conclusion

The MetS severity score was significantly associated with CVD risk. Assessing MetS severity and further ensuring intervention measures according to the different severities of MetS may be more useful in preventing CVD.

Metabolic syndrome and risk of colorectal cancer: A Mendelian randomization study

Background

Observational studies have previously demonstrated a significant relationship among both metabolic syndrome (Mets) and colorectal cancer (CRC). Whether there is a causal link remains controversial.

Objective

To clarify whether Mets and their components have a causal effect on colorectal cancer, we have carried out a bidirectional Mendelian randomization analysis (MR).

Methods

This study started from genome-wide association data for Mets and its 5 components (hypertension, waist circumference, fasting blood glucose, serum triglycerides, and serum high-density lipoprotein cholesterol) and colorectal cancer. Mendelian randomization (MR) techniques were used in the study to examine their associations.

Results

After Benjamini-Hochberg multiple corrections, genetically predicted significant causal link exists between WC (waist circumference) and CRC. The OR was 1.35 (95 % CI: 1.08-1.69; p = 0.0096). Other Mets components (HBP, FBG, TG, HDL), on the other hand, found no evidence of a genetic link between CRC and Mets. In addition, MR results showed that CRC was not causally related to either Mets or the components. We get the same result in the validated dataset.

Conclusion

According to the bidirectional MR investigation shows a significant causal relationship among obesity and CRC in the Mets component but no causal relationship in the opposite direction.

Association between metabolic syndrome and gastric cancer risk: results from the Health Examinees Study

BACKGROUND

Previous studies suggested that metabolic syndrome (MetS) might create a pro-cancer environment and increase cancer incidence. However, evidence on the risk of gastric cancer (GC) was limited. This study aimed to evaluate the association between MetS and its components and GC in the Korean population.

METHODS

Included were 108,397 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem study during 2004-2017. The multivariable Cox proportional was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) on the association between MetS and its components with GC risk. Age was used as the time scale in the analyses. The stratified analysis was performed to determine the joint effect of lifestyle factors and MetS on GC risk in different groups.

RESULTS

During the mean follow-up of 9.1 years, 759 cases of newly diagnosed cancer (408 men and 351 women) were identified. Overall, participants with MetS had a 26% increased risk of GC than those without MetS (HR 1.26; 95% CI 1.07-1.47); the risk increased with the number of MetS components (p for trend 0.01). Hypertriglyceridemia, low HDL-cholesterol, and hyperglycemia were independently associated with the risk of GC. The potential joint effect of MetS and current smokers (p for interaction 0.02) and obesity (BMI ≥ 25.0) (p for interaction 0.03) in GC.

CONCLUSIONS

In this prospective cohort study, we found that MetS were associated with an increased risk of GC in the Korean population. Our findings suggest that MetS may be a potentially modifiable risk factor for GC risk.

Association between metabolic syndrome and colorectal cancer incidence and all-cause mortality: a hospital-based observational study

Background

Metabolic syndrome (MetS) is a worldwide pandemic and complex disorder associated with colorectal cancer (CRC). This study aims to identify the influence of number of MetS components on CRC incidence and mortality, using a national, longitudinal dataset of hospital care in Taiwan.

Methods

Patient data from the Taiwan National Health Insurance Research Database (NHIRD) from 2001 to 2008 were extracted. Individuals with at least one inpatient diagnosis or 2 outpatient visits with any MetS component found within one year were identified and included. Subjects died within 12 months after the presence of MetS components or had any prior cancer were excluded. The study cohort were then divided into two groups: subjects who had more (i.e., 3 to 4) MetS components and those who had fewer (i.e., 1 to 2) MetS components. An 2:1 propensity score (PS) matching were performed to balance the baseline characteristics between the groups. Cox regression analyses were conducted to compare the CRC incidence and all-cause mortality at follow-up between subjects with more MetS components versus fewer components.

Results

After matching, a total of 119,843 subjects (78,274 with 1–2 and 41,569 with 3–4 MetS components) were analyzed. After adjusting for confounders, subjects with 3–4 MetS components had a significantly higher risk of CRC [adjusted hazard ratio (aHR), 1.28; 95% confidence interval (CI), 1.15–1.43, p < 0.001) and all-cause mortality (aHR, 1.13; 95% CI, 1.08–1.17, p < 0.001) than those with only 1–2 MetS components. In stratified analyses, the greatest increased risk of CRC incidence that 3–4 MetS components posed as compared to 1–2 MetS components was seen in subjects without CHD history (aHR, 1.41, 95% CI, 1.23–1.62, p < 0.001). In addition, 3–4 MetS components (vs. 1–2) led to greater all-cause mortality among the subjects < 65y, both genders, with or without CHD, subjects without CKD hisotry, both aspirin users and non-users, users of nonsteroidal anti-inflammatory drugs (NSAIDs), and users of statin.

Conclusion

Compared with 1–2 components, subjects with 3–4 MetS components are at greater risk of CRC and death at follow-up. This study also demonstrates the risks for CRC and all-cause mortality in certain subgroups of individuals with 3–4 MetS components compared to 1–2 components. These findings may help clinicians on the CRC risk stratification according to individuals’ characteristics, as well as to optimize the strategy of MetS surveillance and control in order to prevent CRC.

Metabolic syndrome and the risk of colorectal cancer: a systematic review and meta-analysis

PURPOSE

Observational studies have reported an association between metabolic syndrome (MetS) and colorectal cancer risk with inconsistent risk estimates. We conducted this meta-analysis to evaluate the risk of colorectal cancer in individuals with MetS.

METHODS

PubMed, Embase, and Web of Science were searched for related studies from database inception to 21 January 2021. Risk estimates for colorectal cancer were extracted from individual articles and pooled using a fixed-effect or random-effect model according to the heterogeneity.

RESULTS

MetS was significantly associated with a higher risk of colorectal cancer in both sexes (relative risk [RR] 1.36, 95% confidence interval [CI] 1.26-1.47, P < 0.001), men (RR 1.33, 95% CI 1.21-1.47, P < 0.001), and women (RR 1.34, 95% CI 1.19-1.52, P < 0.001). The risk of colorectal cancer seemed to increase as the number of MetS components rose. Moreover, the high body mass index (BMI)/waist circumference (WC) and hyperglycemia were all significantly associated with a higher risk of colorectal cancer (RR 1.28 [1.20-1.37] and 1.31 [1.14-1.50] in both sexes, RR 1.31 [1.19-1.45] and 1.23 [1.03-1.46] in men, and RR 1.22 [1.02-1.46] and 1.63 [1.16-2.28] in women, respectively).

CONCLUSIONS

MetS was significantly associated with a higher risk of colorectal cancer. The high BMI/WC or hyperglycemia might largely account for this association. Further analysis suggested that, as the number of MetS components increased, the risk of colorectal cancer rose.