ABSTRACT
Background: In cases of atopy, IgE antibodies are formed in reaction to certain environmental factors like house dust mites, pollen, or even food allergens. Some studies have shown an association between atopic diseases and keratoconus. This study aims to determine the prevalence of atopy and its associated factors among keratoconus patients. Materials and Methods: A cross-sectional study was conducted among the Jazan population attending ophthalmology clinics regardless of their sex. Data collection started in August 2020 and finished in mid-June 2021. The sample was selected using the convenience sampling technique, and the total sample size was 83 participants. Data were collected via a questionnaire-based interview that contained 46 questions in the Arabic language. The data collected were analyzed using SPSS software. Results: Family history is the leading predisposing factor for keratoconus (P < 0.001). Also, eye rubbing was a significant (P < 0.015) trigger for keratoconus. However, other factors, including demographic factors such as gender and atopic conditions, did not have any significant association. Conclusion: A combination of genetic and environmental factors is the leading cause of the development of keratoconus; however, family history is the most influential factor, followed by eye rubbing.
ABSTRACT
Introduction Risk factors for developing gallstones are related to disturbances in either cholesterol or bilirubin metabolism in the biliary tract. The risk of forming gallstones can be associated with chronic illnesses, dietary habits, reduced gallbladder motility, and medications. Our study aims to explore the causal relationship between multiple risk factors, including nutritional habits (cheese intake, salad intake, processed meat intake, coffee drinking), smoking behavior, overall obesity measured by body mass index (BMI), lipid biomarkers, total bilirubin and maternal diabetes mellitus (DM) and the development of gallstone disease in two different populations of European ancestry (United Kingdom Biobank (UKB) and FinnGen). Materials and methods Using publicly available genome-wide association studies (GWAS) data, we performed a two-sample Mendelian randomization (MR) to examine the association between risk factors and gallstone development. Exposures used in this study included age of smoking initiation, smoking intensity, coffee intake, cheese intake, salad intake, processed meat intake, BMI, and lipid biomarkers (cholesterol, low-density lipoproteins (LDL), triglycerides (TG), and high-density lipoproteins (HDL)). Current analyses were based on 93 single nucleotide polymorphisms (SNPs) for smoking initiation, four SNPs for smoking intensity, 65 SNPs for cheese intake, three SNPs for coffee intake, 22 SNPs for salad intake, 23 SNPs for processed meat intake, 79 SNPs for BMI, 26 SNPs for maternal DM, 89 SNPs for total bilirubin, 46 SNPs for cholesterol, 41 SNPs for LDL, 55 SNPs for TG, and 89 SNPs for HDL. The outcome in this study is gallstones/cholelithiasis. To evaluate the causal relationships between these risk factors and gallstones, two-sample MR methods were used. TwoSampleMR package in R software version 4.0.5 (R Foundation for Statistical Computing, Vienna, Austria) was used to obtain MR analyses and sensitivity analyses. Results In the UKB, genetic predispositions to smoking initiation, BMI, and total bilirubin were significantly associated with an increased risk of gallstones. The odds of gallstones would increase per 1-SD increase of genetically estimated smoking initiation (OR: 1.004, P=0.008), BMI (OR: 1.02, P<0.001), and total bilirubin (OR: 1.0001, P=0.025). Conversely, genetic predispositions to cheese intake, coffee intake, cholesterol, LDL, and TG were statistically significantly associated with a decreased risk of gallstones (OR=0.99, P=0.014; OR=0.97, P=0.009; OR=0.99, P=0.006; OR=0.99, P=0.01; and OR=0.99, P<0.001, respectively). In FinnGen, genetic predispositions to BMI and total bilirubin were significantly associated with an increased risk of gallstones. The odds of gallstones would increase per 1-SD increase of genetically estimated BMI (OR: 1.7, P<0.001) and total bilirubin (OR: 1.02, P=0.002). Conversely, genetic predispositions to cheese intake, coffee intake, cholesterol, LDL, and TG were statistically significantly associated with a decreased risk of gallstones (OR=0.23, P=0.006; OR=0.42, P=0.041; OR=0.77, P=0.034; OR=0.88, P=0.008; and OR=0.70, P=0.005, respectively). Conclusion Genetically estimated BMI and total bilirubin levels were associated with increased risk of gallstones among the two populations while genetically estimated cheese intake, coffee intake, and cholesterol, LDL, and TG levels factors were consistently associated with reduced risk of gallstones among the two populations.
