The Association between Dietary Insulin Index and Load with Gastric Cancer in Afghanistan.

BACKGROUND: Insulin has a critical role in the pathogenesis of several cancers. We are aware of no study that examined the association between dietary insulin index (DII) and dietary insulin load (DIL) and gastric cancer. OBJECTIVE: This study aimed to investigate the relationship between dietary insulin index and DIL and odds of gastric cancer in Afghanistan. METHODS: In this hospital-based case-control study, we recruited 90 patients with newly-diagnosed gastric cancer and 180 healthy controls in Kabul, Afghanistan. Cases were chosen based on convenience-sampling method from the patients with pathologically confirmed gastric cancer aged between 20 and 75 years that had been referred to Jamhuriat Hospital, Kabul, Afghanistan. We applied a pre-tested food frequency questionnaire for dietary assessment of study participants. DIL and DII were calculated based on earlier publications. Multivariable logistic regression models were applied to examine the association between DII and DIL and gastric cancer. RESULTS: Mean BMI of study participants was 23.55 ± 3.06 kg/m2, of them 73% were males. After adjustment for potential confounders, participants in the top tertile of DII had 3.96 times greater odds for gastric cancer compared with those in the first tertile (95% CI: 1.23, 12.69; P-trend = 0.03). After adjustment for potential confounders, people in the highest tertile of DIL were 3.41 times more likely to have gastric cancer compared with those in the lowest tertile (95% CI: 1.28, 9.09; P-trend = 0.01). These associations remained significant even after further controlling for BMI, family history of cancer, H. pylori infection and salt intake. CONCLUSION: A significant positive association was seen between dietary insulin index and insulin load and odds of gastric cancer in Afghan adults. Prospective cohort studies are required to confirm our findings.

Adherence to the Mediterranean Diet in Relation to Gastric Cancer in Afghanistan.

Background: Despite the adherence to the Mediterranean dietary pattern (MD) being associated with a reduced risk of several cancers, there is no report about the highly prevalent diet-disease associations in Afghanistan, particularly about gastric cancer (GC). Objective: The aim of this study was to investigate the association between MD and GC in Afghanistan. Methods: This hospital-based case-control study was carried out on a total number of 270 subjects (90 cases and 180 controls) aged between 20 and 75 years. Using the convenience-sampling method, cases and controls were selected. Cases were patients with GC whose condition was pathologically confirmed. The controls were apparently healthy people who were matched with cases in terms of age (±5 years) and sex. Assessment of dietary intake was done using a pre-tested food frequency questionnaire, designed specifically for Afghanistan. Adherence to the MD pattern was done based on the scores suggested in earlier studies. Results: Out of 270 studied subjects, 73% were men. We found that subjects in the highest tertile of MD score had 52% decreased odds of GC (OR: 0.48; 95% CI: 0.24-0.98, P-trend = 0.05) compared with those in the lowest tertile. After considering potential environmental factors, age, and sex, the observed association disappeared (OR: 0.43; 95% CI: 0.13-1.38, P-trend = 0.41). After further adjustment for BMI in the last model, we found that participants with the highest MD score were 83% less likely to have GC than those in the lowest tertile (OR: 0.17; 95% CI: 0.03-0.80, P-trend = 0.14). Conclusion: We found that greater adherence to MD might be associated with a lower odds of GC.