Prevalence and Potential Risk Factors of Helicobacter pylori Infection among Asymptomatic Individuals in Kazakhstan.

BACKGROUND: Helicobacter pylori (H. pylori) infection is associated with several risk factors such as demographic, socioeconomic status and personal habits, which vary in different populations. This is the most up-to-date data on H. pylori prevalence and potential risk factors for H. pylori infection among asymptomatic middle-aged individuals in Kazakhstan. METHODS: Apparently healthy individuals aged 40 to 64, who took part in the health control in the outpatient clinic, were invited to participate in the study; answered a questionnaire, donated a blood sample. The antibodies to H. pylori were analysed by latex agglutination method. The baseline characteristics of study subjects with or without H. pylori infection were compared using the Chi-square test. Odds ratio (OR) and 95% confidence intervals (CI) for the association between H. pylori infection and potential risk factors were estimated using multivariable logistic regression models. RESULTS: Altogether 166 subjects (59% male; the median age - 51 years old) were included; 104 (62.7%) were H. pylori positive. There were no statistically significant differences between H. pylori positive and H. pylori negative groups in respect to the gender, anthropometric measurements, socioeconomic factors and personal habits. The multiple variable analysis showed that age (OR, 1.99; 95% CI, 1.03 - 3.86; P=0.04) and increased salt intake (OR, 2.21; 95% CI, 1.12 - 4.35; P=0.02) were associated with H. pylori infection. CONCLUSIONS: More than half of the study subjects were infected with H. pylori in Kazakhstan. The prevalence of H. pylori infection was independently associated with older age and regular high salt consumption.

Prevalence of Atrophic Gastritis in Kazakhstan and the Accuracy of Pepsinogen Tests to Detect Gastric Mucosal Atrophy.

BACKGROUND: Atrophic gastritis is considered precursor condition for gastric cancer. There is so far limited evidence on the performance of pepsinogens for atrophy detection in Central Asia. The aim of our study was to detect the prevalence of atrophic gastritis in the asymptomatic adult population in Kazakhstan as well as address the accuracy of pepsinogen testing in atrophy detection. METHODS: Healthy individuals aged 40-64 were included. Upper endoscopy and pepsinogens (PG) evaluation were performed. PG were analysed in plasma by latex agglutination. Cut off values were used to define decreased PG values (PGR ≤ 3 and PG I ≤ 70 ng/mL); severely decreased PG values (PGR ≤ 2 and PG I ≤ 30 ng/mL). Biopsies were analyzed and obtained according to the updated Sydney System. PG test sensitivity, specificity and overall accuracy were assessed using the histological diagnosis as the "gold standard". RESULTS: Altogether 157 individuals - female 40,1% and male 59,9% were included. Histologically, moderate to severe corpus atrophy, was present only in 1,3% cases. From all study subjects, 26,8% had decreased plasma PG values with cut-off values PGR ≤ 3 and PG I ≤ 70 ng/mL. The sensitivity of the PG test with this cut-off values was 50,0%, specificity 73,5%, overall accuracy 73,2% for detection of moderate to severe atrophy in the corpus. The sensitivity of PG test with cut-off values PGR ≤ 2 and PG I ≤30 ng/mL was 50,0%, specificity 90,9% and overall accuracy 90,4%. CONCLUSIONS: The prevalence of gastric mucosal atrophy was low in the Kazakh population. Serological PG test screening nevertheless can play an important role in the diagnosis of gastric precancerous lesions. However, the diagnostic accuracy of the PG test is mainly dependent on the cut-off values for positive results.