Pooling controls from nested case-control studies with the proportional risks model.

The standard approach to regression modeling for cause-specific hazards with prospective competing risks data specifies separate models for each failure type. An alternative proposed by Lunn and McNeil (1995) assumes the cause-specific hazards are proportional across causes. This may be more efficient than the standard approach, and allows the comparison of covariate effects across causes. In this paper, we extend Lunn and McNeil (1995) to nested case-control studies, accommodating scenarios with additional matching and non-proportionality. We also consider the case where data for different causes are obtained from different studies conducted in the same cohort. It is demonstrated that while only modest gains in efficiency are possible in full cohort analyses, substantial gains may be attained in nested case-control analyses for failure types that are relatively rare. Extensive simulation studies are conducted and real data analyses are provided using the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) study.

Relation between the Dantu blood group variant and bacteraemia in Kenyan children: a population-based case control study.

BACKGROUND: The Dantu blood group variant protects against P. falciparum infections but its wider consequences have not been previously explored. Here, we investigate the impact of Dantu on susceptibility to bacteraemia. METHODS: We conducted a case-control study in children presenting with community-acquired bacteraemia to Kilifi County Hospital in Kenya between 1998 and 2010. We used logistic regression to test for associations between the Dantu marker SNP rs186873296 A>G and both all-cause and pathogen-specific bacteraemia under an additive model. We used date of admission as a proxy measure of malaria transmission intensity, given known differences in malaria prevalence over the course of the study. RESULTS: Dantu was associated with protection from all-cause bacteraemia (OR=0.81, p=0.014), the association being greatest in homozygotes (OR=0.30, p=0.013). This protection was shared across the major bacterial pathogens but, notably, was only significant during the era of high malaria-transmission pre-2003 (OR=0.79, p=0.023). CONCLUSIONS: Consistent with previous studies showing the indirect impact on bacteraemia risk of other malaria-associated red cell variants, our study also shows that Dantu is protective against bacteraemia via its effect on malaria risk. Dantu does not appear to be under balancing selection through an increased risk of bacterial infections.

Exposure to antibiotics and risk of latent autoimmune diabetes in adults and type 2 diabetes: results from a Swedish case-control study (ESTRID) and the Norwegian HUNT study.

AIMS/HYPOTHESIS: Some studies find an increased risk of type 1 diabetes in children exposed to antibiotics. We investigated if exposure to antibiotics increases the risk of latent autoimmune diabetes in adults (LADA) and type 2 diabetes. METHODS: We used data from a Swedish case-control study (Epidemiological Study of Risk Factors for LADA and Type 2 Diabetes [ESTRID]: LADA, n=597; type 2 diabetes, n=2065; control participants matched on participation time, n=2386) and a case-control study nested within the Norwegian Trøndelag Health Study (HUNT) (n=82/1279/2050). Anatomical Therapeutic Chemical (ATC) codes indicating antibiotic dispensations were retrieved from the Swedish National Prescribed Drug Register and Norwegian Prescription Database. Multivariable adjusted ORs with 95% CIs were estimated by conditional logistic regression and pooled using fixed-effects inverse-variance weighting. RESULTS: We observed no increased risk of LADA with exposure to antibiotics up to 1 year (ORpooled 1.15, 95% CI 0.93, 1.41) or 1-5 years (ORpooled 0.98, 95% CI 0.80, 1.20) prior to diagnosis/matching for one or more vs no dispensation of any type of antibiotic. An increased risk was observed for one or more vs no dispensations of narrow-spectrum antibiotics, but not broad-spectrum antibiotics, 6-10 years prior to LADA diagnosis (ORpooled 1.39, 95% CI 1.01, 1.91), which was driven by the Swedish data. There was little evidence of an increased risk of type 2 diabetes associated with antibiotic exposure 1-10 years prior to diagnosis. CONCLUSIONS/INTERPRETATION: We found no evidence that exposure to broad-spectrum antibiotics up to 10 years prior to diagnosis increases the risk of LADA. There was some indication of increased LADA risk with exposure to narrow-spectrum antibiotics, which warrants further investigation.

Plasma metabolomics profiles and breast cancer risk.

BACKGROUND: Breast cancer (BC) is the most common cancer in women and incidence rates are increasing; metabolomics may be a promising approach for identifying the drivers of the increasing trends that cannot be explained by changes in known BC risk factors. METHODS: We conducted a nested case-control study (median followup 6.3 years) within the New York site of the Breast Cancer Family Registry (BCFR) (n = 40 cases and 70 age-matched controls). We conducted a metabolome-wide association study using untargeted metabolomics coupling hydrophilic interaction liquid chromatography (HILIC) and C18 chromatography with high-resolution mass spectrometry (LC-HRMS) to identify BC-related metabolic features. RESULTS: We found eight metabolic features associated with BC risk. For the four metabolites negatively associated with risk, the adjusted odds ratios (ORs) ranged from 0.31 (95% confidence interval (CI): 0.14, 0.66) (L-Histidine) to 0.65 (95% CI: 0.43, 0.98) (N-Acetylgalactosamine), and for the four metabolites positively associated with risk, ORs ranged from 1.61 (95% CI: 1.04, 2.51, (m/z: 101.5813, RT: 90.4, 1,3-dibutyl-1-nitrosourea, a potential carcinogen)) to 2.20 (95% CI: 1.15, 4.23) (11-cis-Eicosenic acid). These results were no longer statistically significant after adjusting for multiple comparisons. Adding the BC-related metabolic features to a model, including age, the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) risk score improved the accuracy of BC prediction from an area under the curve (AUC) of 66% to 83%. CONCLUSIONS: If replicated in larger prospective cohorts, these findings offer promising new ways to identify exposures related to BC and improve BC risk prediction.

Pre-diagnostic plasma inflammatory proteins and risk of hepatocellular carcinoma in three population-based cohort studies from the United States and the United Kingdom.

Previous studies suggest a role for inflammation in hepatocarcinogenesis. However, no study has comprehensively evaluated associations between circulating inflammatory proteins and risk of hepatocellular carcinoma (HCC) among the general population. We conducted a nested case-control study in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) with 56 pairs of incident HCC cases and controls. External validation was performed in the UK Biobank (34 HCC cases and 48,471 non-HCC controls). Inflammatory protein levels were measured in pre-diagnostic plasma using the Olink® Inflammation Panel. We used conditional logistic regression to calculate multivariable odds ratios (ORs) with 95% confidence intervals (CIs) for associations between a 1-standard deviation (SD) increase in biomarker levels and HCC risk, considering a statistically significant threshold of false discovery rate (FDR)-adjusted p < .05. In the NHS/HPFS, among 70 analyzed proteins with call rates >80%, 15 proteins had significant associations with HCC risk (pFDR < .05). Two proteins (stem cell factor, OR per SD = 0.31, 95% CI = 0.16-0.58; tumor necrosis factor superfamily member 12, OR per SD = 0.51, 95% CI = 0.31-0.85) were inversely associated whereas 13 proteins were positively associated with risk of HCC; positive ORs per SD ranged from 1.73 for interleukin (IL)-10 to 2.35 for C-C motif chemokine-19. A total of 11 proteins were further replicated in the UK Biobank. Seven of the eight selected positively associated proteins also showed positive associations with HCC risk by enzyme-linked immunosorbent assay, with ORs ranging from 1.56 for IL-10 to 2.72 for hepatocyte growth factor. More studies are warranted to further investigate the roles of these observed inflammatory proteins in HCC etiology, early detection, risk stratification, and disease treatment.

Pelvic inflammatory disease and risk of borderline ovarian tumors: A national population-based case-control study in Sweden.

The resemblance between fallopian tube cells and serous borderline ovarian tumors (BOTs) suggests a potential origin link, with salpingitis proposed as a contributing factor in the pathogenesis of BOT. This study aimed to explore the potential association between pelvic inflammatory disease (PID) and the risk of developing BOT. A national population-based case-control study in Sweden included women with BOT between 1999 and 2020 and 10 matched controls. Data from nationwide registers were analyzed using conditional logistic regression, adjusting for age, residential district, educational level and parity. Among 4782 cases and 45,167 controls, 2.0% of cases and 1.3% of controls had a history of PID. Previous PID was associated with an increased risk of BOT overall (aOR, 1.48; 95% CI, 1.19-1.85). Significant association was observed with serous tumors (aOR, 1.76; 95% CI, 1.36-2.29), while not with mucinous tumors (aOR, 0.95; 95% CI, 0.60-1.49). A dose-response relationship between number of PID episodes and serous BOT risk was noted (Ptrend < .001). This study demonstrates that PID is associated with increased risk of serous BOT, with a dose response relationship. The study highlights the potential serious implications of upper reproductive tract infections and inflammation. This underscores the need for further investigation of biological mechanisms and possible impact of PID on serous BOT development.

The landscape of etiological patterns of hepatocellular carcinoma and intrahepatic cholangiocarcinoma in Thailand.

Thailand is among countries with the highest global incidence and mortality rates of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). While viral hepatitis and liver fluke infections have been associated with HCC and iCCA, respectively, other environmental risk factors, overall risk factor commonality and combinatorial roles, and effects on survival have not been systematically examined. We conducted a TIGER-LC consortium-based population study covering all high-incidence areas of both malignancies across Thailand: 837 HCC, 1474 iCCA, and 1112 controls (2011-2019) were comprehensively queried on lifelong environmental exposures, lifestyle, and medical history. Multivariate logistic regression and Cox proportional hazards analyses were used to evaluate risk factors and associated survival patterns. Our models identified shared risk factors between HCC and iCCA, such as viral hepatitis infection, liver fluke infection, and diabetes, including novel and shared associations of agricultural pesticide exposure (OR range of 1.50; 95% CI: 1.06-2.11 to 2.91; 95% CI: 1.82-4.63) along with vulnerable sources of drinking water. Most patients had multiple risk factors, magnifying their risk considerably. Patients with lower risk levels had better survival in both HCC (HR 0.78; 95% CI: 0.64-0.96) and iCCA (HR 0.84; 95% CI: 0.70-0.99). Risk factor co-exposures and their common associations with HCC and iCCA in Thailand emphasize the importance for future prevention and control measures, especially in its large agricultural sector. The observed mortality patterns suggest ways to stratify patients for anticipated survivorship and develop plans to support medical care of longer-term survivors, including behavioral changes to reduce exposures.

The Healthy Participant Effect: insights and results from a population-based case-control study on breast cancer.

Agreement to participate in case-control studies has become low. Healthy participant bias resulting from differential response proportions in cases and controls can distort results; however, the magnitude of bias is difficult to assess. We investigated the effect in a large population-based case-control study on breast cancer, with a participation rate of 43.4% and 64.1% for controls and cases. We performed a mortality follow-up in 2020 for 3,813 cases and 7,335 controls recruited between 2002-2005. Standardized mortality ratios (SMR) for overall mortality and selected causes of death were estimated. The mean age at recruitment was 63.1 years. The overall mortality for controls was 0.66 times lower (95%CI 0.62-0.69) than for the reference population. For causes of death other than breast cancer, SMRs were similar in cases and controls (0.70 and 0.64). Higher education was associated with lower SMRs in both cases and controls. Options for adjusting the healthy participant bias are limited if the true risk factor distribution in the underlying population is unknown. However, a relevant bias in this particular case-control study is considered unlikely since a similar healthy participant effect was observed for both controls and cases.

Design of a Location-Based Case-Control Study of Built Environment Risk Factors for Pedestrian Fatalities in the U.S.

The location-based case-control design is a useful approach for studies where the exposures of interest are aspects of the environment around the location of a health event such as a pedestrian fatality. In this design locations are the unit of analysis and an enumerated cohort of locations are followed through time for the health events of interest and a case-control study of locations is nested within the cohort. Locations where events occurred (case-locations) are compared to matched locations where these events did not occur (control-locations). We describe the application of this design to the issue of pedestrian fatalities using a cohort of 9,612,698 intersections, 17,737,728 road segments, and 222,318 entrance/exit ramp segments that existed in 2017 across all 384 U.S. Metropolitan Statistical Areas. This cohort of locations was followed up from Jan 1, 2017 to Dec 31, 2018 for pedestrian fatalities using the National Highway Traffic Safety Administration Fatality Analysis Reporting System. In total, 10,587 fatalities were identified as having occurred on cohort locations and 21,174 matched control locations were selected using incidence density sampling. Geographic information systems, spatially linked administrative data sets and virtual neighborhood audits via Google Street View are underway to characterize study locations.

Signal detection statistics of adverse drug events in hierarchical structure for matched case-control data.

The tree-based scan statistic is a data mining method used to identify signals of adverse drug reactions in a database of spontaneous reporting systems. It is particularly beneficial when dealing with hierarchical data structures. One may use a retrospective case-control study design from spontaneous reporting systems (SRS) to investigate whether a specific adverse event of interest is associated with certain drugs. However, the existing Bernoulli model of the tree-based scan statistic may not be suitable as it fails to adequately account for dependencies within matched pairs. In this article, we propose signal detection statistics for matched case-control data based on McNemar's test, Wald test for conditional logistic regression, and the likelihood ratio test for a multinomial distribution. Through simulation studies, we demonstrate that our proposed methods outperform the existing approach in terms of the type I error rate, power, sensitivity, and false detection rate. To illustrate our proposed approach, we applied the three methods and the existing method to detect drug signals for dizziness-related adverse events related to antihypertensive drugs using the database of the Korea Adverse Event Reporting System.

A case-control study and molecular epidemiology of yersiniosis in Aotearoa New Zealand.

The objective of this study was to determine risk factors and sources attributed to yersiniosis in Aotearoa New Zealand (NZ). A risk factor questionnaire was administered to 247 notified yersiniosis cases and 258 control participants from the Canterbury and/or Wellington regions of NZ. Yersinia sp. isolates from clinical cases and a range of food sources were whole-genome sequenced and genetically compared. Yersinia enterocolitica (YE) bioserotype 2/3, O:9 [McNally multi-locus sequence type (ST) 12] and YE Biotype (BT) 1A (46 different STs) predominated within the consented cases (45 and 27%, respectively). Exposure to pork was identified as a significant risk factor for cases associated with YE ST12. The presence of YE ST12 was confirmed in retail raw meat, primarily raw pork. Single-nucleotide polymorphism (SNP) analysis identified multiple genomically very closely related clusters (0-5 SNPs) of YE ST12, predominately from raw pork with clinical cases from one or both regions. Risk factors associated with YE BT 1A included the consumption of cooked seafood, sushi, tofu, and some vegetable types. Analysis of specific risk factors and SNP analysis, combined, indicate that raw pork is a significant risk factor for exposure and infection to pathogenic YE cases, but not BT 1A cases.

Screening history and risk of death from prostate cancer: a nested case-control study within the screening arm of the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC).

PURPOSE: We assessed the risk of death from prostate cancer (PCa) in relation to men's screening histories, i.e., screening attendance among men who were offered screening. METHODS: Men in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) screening arm were invited to up to three screening rounds with the serum prostate-specific antigen (PSA) test at 4-year intervals during 1996-2007. Case subjects (n = 330) were men who died from PCa. Each case was matched to five controls (n = 1544) among the men who were free of PCa. Screening history was defined as (1) never/ever attended screening prior to the case diagnosis; (2) attended at the first screening round; and (3) recency of screening, calculated as the time from last screening attendance to the date of case diagnosis. The association between screening history and the risk of death from PCa was estimated by odds ratios (OR) with 95% confidence intervals (CI) using conditional logistic regression. RESULTS: Having ever attended screening versus never attended was associated with a reduced risk of PCa death (OR 0.60, 95% CI 0.45-0.81) and a similar association was found for those attended (versus not attended) the first screening round (OR 0.67, 95% CI 0.51-0.87). The effect by time since last screen for the risk of PCa death was significantly lower 2-7 years since last screen. CONCLUSION: Among men invited to screening, subjects who attended any PSA screening during the previous 19 years had a 40% reduction in PCa mortality compared to non-screened men.

Subsequent primary neoplasms after childhood cancer therapy - design and description of the German nested case-control study STATT-SCAR.

BACKGROUND: Subsequent primary neoplasms (SPN) are among the most severe late effects and the second most frequent cause of death in childhood cancer patients. In this paper we introduce method and properties of the STATT-SCAR study (Second Tumor After Tumor Therapy, Second Cancer After Radiotherapy), which is a joint nested matched case-control study to evaluate the impact of chemotherapy (STATT) as well as radiotherapy (SCAR) on the risk of developing a SPN. METHODS: Based on the cohort of the German childhood cancer registry (GCCR), we selected patients diagnosed with a first neoplasm before age 15 or younger between 1980 and 2014. We selected those with a SPN at least half a year after the first neoplasm, and matched up to four controls to each case. Therapy data were acquired from various sources, including clinical study centers and treating hospitals. To analyze the impact of radiotherapy, organ doses were estimated by using reconstructed treatment plans. The effect of chemotherapy was analyzed using substance groups summarized after isotoxic dose conversion. RESULTS: 1244 cases with a SPN were identified and matched with 4976 controls. Treatment data were acquired for 83% of all match groups (one case and at least one control). Based on preliminary analyses, 98% of all patients received chemotherapy and 54% of all patients were treated with radiotherapy. CONCLUSIONS: Based on our data, detailed analyses of dose response relationships and treatment element combinations are possible, leading to a deeper insight into SPN risks after cancer treatments. TRIAL REGISTRATION: The study is registered at the German clinical trial register (DRKS) under number DRKS00017847 [45].

Ambient polycyclic aromatic hydrocarbon exposure and breast cancer risk in a population-based Canadian case-control study.

PURPOSE: Polycyclic aromatic hydrocarbons (PAHs) represent a class of ubiquitous pollutants recognized as established human carcinogens and endocrine-disrupting chemicals. PAHs have seldom been modeled at the population-level in epidemiological studies. Fluoranthene is a prevalent PAH in urban settings and correlates with the occurrence of other PAHs. The purpose of this study was to evaluate associations between long-term residential exposure to ambient PAHs and breast cancer risk, both pre- and post-menopausal, in Canada. METHODS: Using the National Enhanced Cancer Surveillance System (NECSS), a national-scale Canadian population-based case-control study, annual fluoranthene exposures were estimated using the GEM-MACH-PAH chemical transport model on the basis of geocoded residential histories throughout a 20-year exposure window. Odds ratios (ORs) and 95% confidence intervals (CIs) controlling for potential confounders were estimated using logistic regression. Separate analyses were conducted for Ontario and national samples given a finer-resolution exposure surface and additional risk factor information available for Ontario. RESULTS: Positive associations were observed between fluoranthene exposure and premenopausal breast cancer, with inconsistent findings for postmenopausal breast cancer. For premenopausal breast cancer, adjusted ORs of 2.48 (95% CI: 1.29, 4.77) and 1.59 (95% CI: 1.11, 2.29) were observed when comparing the second highest category of exposure to the lowest, among the Ontario and national samples, respectively. For postmenopausal breast cancer, adjusted ORs were 1.10 (95% CI: 0.67, 1.80) and 1.33 (95% CI: 1.02, 1.73). Associations for the highest level of exposure, across both samples and menopausal strata, were non-significant. CONCLUSION: This study provides support for the hypothesis that ambient PAH exposures increase the risk of premenopausal breast cancer.

Factors affecting quality of life in hepatitis B patients in Herat, Afghanistan: A case-control study.

Hepatitis B virus is a global health concern with a high death rate in Afghanistan. Limited data exist on the disease's impact on quality of life in low-resource settings. This case-control study aims to identify potential risk factors and assess the quality of life among hepatitis B patients in Herat, Afghanistan, with a focus on sex differences. Understanding these factors can inform prevention, care, and sex-specific interventions. A cross-sectional study conducted at Herat Regional Hospital examined hepatitis B patients above 18 years old, between October 2020 and February 2021. The control group consisted of age and sex-matched individuals without a history of hepatitis B. Data were collected through a structured questionnaire covering socio-demographic characteristics, signs and symptoms of hepatitis B, and the SF-36 questionnaire for measuring the quality of life of study participants. Statistical analysis was performed using multivariate General Linear Models, and logistic regression. We identified several potential risk factors for hepatitis B infection, including male sex, younger age groups, tobacco use, lower education levels, rural residence, family history, weak social networks, specific family structures and underlying chronic diseases (p < .05). The study found that hepatitis B cases had significantly lower mean scores across all SF-36 components, indicating an overall reduced quality of life (p < .05). These differences were more pronounced in males, although females had lower scores in most components. Role limitations due to physical and emotional health were particularly affected. These findings highlight the urgent need for targeted interventions, sex-specific strategies, improved healthcare access and comprehensive policies. These findings can inform prevention efforts to improve the overall quality of life of people with hepatitis B in Afghanistan.

IVF and risk of Type 1 diabetes mellitus: a population-based nested case-control study.

STUDY QUESTION: Is the mode of conception (natural, subfertility and non-IVF, and IVF) associated with the risk of Type 1 diabetes mellitus among offspring? SUMMARY ANSWER: The risk of Type 1 diabetes in offspring does not differ among natural, subfertility and non-IVF, and IVF conceptions. WHAT IS KNOWN ALREADY: Evidence has shown that children born through IVF have an increased risk of impaired metabolic function. STUDY DESIGN, SIZE, DURATION: A population-based, nested case-control study was carried out, including 769 children with and 3110 children without Type 1 diabetes mellitus within the prospective cohort of 2 228 073 eligible parent-child triads between 1 January 2004 and 31 December 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Using registry data from Taiwan, the mode of conception was divided into three categories: natural conception, subfertility, and non-IVF (indicating infertility diagnosis but no IVF-facilitated conception), and IVF conception. The diagnosis of Type 1 diabetes mellitus was determined according to the International Classification of Diseases, 9th or 10th Revision, Clinical Modification. Each case was matched to four controls randomly selected after matching for child age and sex, residential township, and calendar date of Type 1 diabetes mellitus occurrence. MAIN RESULTS AND THE ROLE OF CHANCE: Based on 14.3 million person-years of follow-up (median, 10 years), the incidence rates of Type 1 diabetes were 5.33, 5.61, and 4.74 per 100 000 person-years for natural, subfertility and non-IVF, and IVF conceptions, respectively. Compared with natural conception, no significant differences in the risk of Type 1 diabetes were observed for subfertility and non-IVF conception (adjusted odds ratio, 1.04 [95% CI, 0.85-1.27]) and IVF conception (adjusted odds ratio, 1.00 [95% CI, 0.50-2.03]). In addition, there were no significant differences in the risk of Type 1 diabetes according to infertility source (male/female/both) and embryo type (fresh/frozen). LIMITATIONS, REASONS FOR CAUTION: Although the population-level data from Taiwanese registries was used, a limited number of exposed cases was included. We showed risk of Type 1 diabetes was not associated with infertility source or embryo type; however, caution with interpretation is required owing to the limited number of exposed events after the stratification. The exclusion criterion regarding parents' history of diabetes mellitus was only applicable after 1997, and this might have caused residual confounding. WIDER IMPLICATIONS OF THE FINDINGS: It has been reported that children born to parents who conceived through IVF had worse metabolic profiles than those who conceived naturally. Considering the findings of the present and previous studies, poor metabolic profiles may not be sufficient to develop Type 1 diabetes mellitus during childhood. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from Shin Kong Wu Ho-Su Memorial Hospital (No. 109GB006-1). The funders had no role in considering the study design or in the collection, analysis, interpretation of data, writing of the report, or decision to submit the article for publication. The authors have no competing interests to disclose. TRIAL REGISTRATION NUMBER: N/A.

Use of Antiperspirant Products and Risk of Breast Cancer: A Meta-Analysis of Case-Control Studies.

Although several observational studies have reported a link between the use of underarm cosmetic products and the risk of breast cancer, the findings remain inconsistent. This study aimed to investigate these associations using a meta-analysis of observational studies. In the meta-analysis of seven case-control studies, we found no association between the use of underarm antiperspirants or deodorants and the risk of breast cancer (OR = 0.96, 95%CI 0.78-1.17; I2 = 60.0%). Further prospective cohort studies that provide a higher level of evidence are warranted to confirm our findings.

Consumption of Sugar-Sweetened Soft Drinks and Risk of Gastrointestinal Cancer: A Systematic Review and Meta-Analysis of Observational Studies.

INTRODUCTION: Previous observational studies have reported inconsistent findings on the association between consumption of sugar-sweetened soft drinks (SSSDs) and the risk of gastrointestinal (GI) cancer. This study investigated the associations between SSSD consumption and the risk of GI cancer using a systematic review and meta-analysis. METHODS: Observational epidemiological studies were searched from the PubMed and EMBASE databases until June 2021. We conducted a meta-analysis of all included studies and subgroup meta-analyses based on various factors. RESULTS: In a meta-analysis of 27 studies with nine case-control studies and 18 cohort studies, the consumption of SSSDs was modestly associated with an increased risk of GI cancer (odds ratio [OR]/relative risk [RR]: 1.08; 95% confidence interval [CI]: 1.01-1.16), with a significant positive dose-response relationship. In the subgroup meta-analysis by study design, there was a significant positive association between the consumption of SSSDs and GI cancer in cohort studies (RR: 1.11; 95% CI: 1.03-1.20; n = 18), but not in case-control studies. In the subgroup meta-analysis by type of cancer, consumption of SSSDs was significantly associated with an increased risk of colorectal cancer (OR/RR: 1.13; 95% CI: 1.07-1.19). CONCLUSIONS: This meta-analysis suggests that SSSD consumption significantly increases the risk of GI cancer, specifically colorectal cancer.

Maternal overweight and obesity modify the association of serum fibroblast growth factor 21 levels with gestational diabetes mellitus: A nested case-control study.

AIMS: To examine the prospective association between fibroblast growth factor 21 (FGF21) and risk of gestational diabetes mellitus (GDM) and the modifying effect of overweight/obesity for this association. METHODS: Serum FGF21 levels were measured at 6-15 weeks of gestation among 332 GDM cases and 664 matched controls. Conditional logistic regression was used to evaluate its association with GDM risk. Interaction analyses on multiplicative and additive scales were conducted to investigate the modifying effect of overweight/obesity. RESULTS: Elevated FGF21 levels were associated with a higher risk of GDM in multivariable models, but the positive association was attenuated after further adjustment for pre-pregnancy body mass index (BMI). A significant multiplicative interaction was noted between FGF21 (both continuous and dichotomous) and pre-pregnancy BMI (p for interaction = 0.049 and 0.03), and the association was only significant in participants with pre-pregnancy BMI ≥24 kg/m2 . When participants were grouped based on pre-pregnancy BMI (≥24 and <24 kg/m2 ) and FGF21 levels (≥median and

Association of plasma advanced glycation end-products and their soluble receptor with type 2 diabetes among Chinese adults.

AIMS: Population-based evidence regarding circulating advanced glycation end-products (AGEs) and the risk of type 2 diabetes (T2D) is conflicting and insufficient. We aimed to examine the association of plasma AGEs and plasma soluble receptors for AGEs (sRAGE) with T2D. MATERIALS AND METHODS: We conducted a hospital-based case-control study including 1072 pairs (53.9 ± 9.7 years, 56.0% male) of newly diagnosed T2D and age- and sex-matched controls. We further performed a nested case-control study within an ongoing prospective cohort consisting of 127 incident T2D cases and 381 well-matched controls (62.2 ± 5.1 years, 71.7% male). Plasma AGEs were detected using liquid chromatography-tandem mass spectrometry, and plasma sRAGE was measured by enzyme-linked immunosorbent assay. Conditional logistic regression was used to evaluate the association of plasma AGEs and sRAGE concentrations with T2D. RESULTS: Higher plasma AGEs and lower sRAGE concentrations were associated with higher odds of T2D. The multivariable-adjusted odds ratios of T2D comparing the highest with the lowest quartile levels were 3.28 (95% CI: 2.14, 5.02) for plasma AGEs and 0.25 (95% CI: 0.16, 0.39) for plasma sRAGE. Participants in the highest quartile of plasma AGEs and the lowest quartile of sRAGE concentrations had the greatest odds of T2D. The positive association of AGEs and inverse association of sRAGE with T2D risk was confirmed in the replication-nested case-control study. CONCLUSIONS: Increased circulating AGEs and decreased sRAGE concentrations were associated with elevated T2D risk. Our findings may have implications for the strategies of T2D prevention and management.