A population based case-control study of association between dietary calcium intake and ulcerative colitis in adults

Dairy Consumption and Inflammatory Bowel Disease among Arab Adults: A Case-Control Study and Meta-Analysis

BACKGROUND

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is a complex disease with increasing global incidence and prevalence. Although dairy consumption has been linked to various chronic diseases, its relationship with IBD remains uncertain. Additionally, there is a lack of data on this topic from Arab countries. This study aimed to investigate the association between dairy consumption and IBD through a case-control study among Arab populations, followed by a meta-analysis of available studies.

METHOD

First, we used data from 158 UC patients, 244 CD patients, and 395 controls attending a polyclinic in Riyadh, Saudi Arabia. All participants were aged ≥ 18 years. Logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) of UC and CD for individuals who reported the highest versus the lowest frequencies of dairy consumption. Next, we conducted a meta-analysis, combining our results with those from other eligible studies after searching several databases. We used the I2 statistics to examine statistical heterogeneity across studies and the regression test for funnel plot asymmetry to assess publication bias.

RESULTS

The case-control study showed a negative association between frequent dairy consumption and UC (OR (95% CI) = 0.64 (0.41, 1.00)) but not CD (OR (95% CI) = 0.97 (0.65, 1.45)). In the meta-analysis, the highest frequencies of dairy consumption were negatively associated with both UC and CD: ORs (95% CIs) = 0.82 (0.68, 0.98) and 0.72 (0.59, 0.87), respectively. A moderate heterogeneity across studies was noticed in the UC meta-analysis (I2 = 59.58%) and the CD meta-analysis (I2 = 41.16%). No publication bias was detected.

CONCLUSIONS

Frequent dairy consumption could protect against the development of UC and CD, suggesting potential dietary recommendations in the context of IBD prevention.

Association between dietary calcium to Phosphorus Ratio and the odds of ulcerative colitis: A case-control study

Background & aims

Ulcerative colitis (UC) is a recurrent, inflammatory, autoimmune intestinal disease. The dietary calcium to phosphorus (Ca:P) ratio is suggested to affect the inividuals' normal metabolic and inflammatory pathways. The present study aimed to investigate the association between dietary Ca:P ratio and the odds of developing UC in a case-control format.

Methods

The study included sixty-two currently diagnosed UC patients and one hundred twenty-four matched controls, designed as a case-control study. The dietary intakes of the participants were assessed by a food frequency questionnaire (FFQ), and the dietary Ca:P ratio was calculated. The association between tertiles of Ca:P ratio and UC was examined using the logistic regression. P-values <0.05 were considered as significant.

Results

The study sample consisted of participants with an average age of 36.63 ± 12.42 years and a mean body mass index (BMI) of 25.39 ± 3.82 kg/m2. The overall energy-adjusted ratio of Ca:P was 0.74 ± 0.11. In the multivariate model, after adjustment for potential confounders, participants in the third tertile of dietary Ca:P ratio had a lower odds of developing UC compared to the lowest tertlie (OR: 0.34, 95% CI: 0.13-0.87; p = 0.026).

Conclusion

Our results indicate that a higher ratio of dietary Ca:P ratio might be protective against developing UC. However, further studies are warranted to examine this association in various populations.

Calcium Supplementation on Glucose Tolerance, Oxidative Stress, and Reproductive Outcomes of Diabetic Rats and Their Offspring

Diabetes mellitus increases the risk of obstetric complications, morbidity, and infant mortality. Controlled nutritional therapy with micronutrients has been employed. However, the effect of calcium (Ca2+) supplementation on diabetic pregnancy is unclear. We aimed to evaluate whether diabetic rats supplemented with Ca2+ during pregnancy present better glucose tolerance, redox status, embryonic and fetal development, newborn weight, and the prooxidant and antioxidant balance of male and female pups. For this, newborn rats received the beta-cytotoxic drug streptozotocin for inducing diabetes on the day of birth. In adulthood, these rats were mated and treated with Ca2+ twice a day from day 0 to day 20 of pregnancy. On day 17, the pregnant rats were submitted to the oral glucose tolerance test (OGTT). At the end of pregnancy, they were anesthetized and killed to collect blood and pancreas samples. The uterine horns were exposed for an evaluation of maternal reproductive outcomes and embryofetal development, and the offspring's liver samples were collected for redox status measurement. Nondiabetic and diabetic rats supplemented with Ca2+ showed no influence on glucose tolerance, redox status, insulin synthesis, serum calcium levels, and embryofetal losses. The reduced rate of newborns classified as adequate for gestational age (AGA) and higher rates of LGA (large) and small (LGA) newborns and higher -SH and GSH-Px antioxidant activities in female pups were observed in diabetic dams, regardless of supplementation. Thus, maternal supplementation caused no improvement in glucose tolerance, oxidative stress biomarkers, embryofetal growth and development, and antioxidants in pups from diabetic mothers.