The prevalence of infection with hepatitis A virus (HAV), HBV, HCV, HDV, and HEV was evaluated in 249 apparently healthy individuals, including 122 inhabitants in Ulaanbaatar, the capital city of Mongolia, and 127 age-and sex-matched members of nomadic tribes who lived around the capital city. Overall, hepatitis B surface antigen (HBsAg) was detected in 24 subjects (10%), of whom 22 (92%) had detectable HBV DNA. Surprisingly, HDV RNA was detectable in 20 (83%) of the 24 HBsAg-positive subjects. HCV-associated antibodies were detected in 41 (16%) and HCV RNA was detected in 36 (14%) subjects, none of whom was coinfected with HBV, indicating that HBV/HCV carriers account for one-fourth of this population. Antibodies to HAV and HEV were detected in 249 (100%) and 28 (11%) subjects, respectively. Of 22 HBV DNA-positive subjects, genotype D was detected in 21 subjects and genotype F was detected in 1 subject. All 20 HDV isolates recovered from HDV RNA-positive subjects segregated into genotype I, but these differed by 2.1 to 11.4% from each other in the 522-to 526-nucleotide sequence. Of 36 HCV RNA-positive samples, 35 (97%) were genotype 1b and 1 was genotype 2a. Reflecting an extremely high prevalence of hepatitis virus infections, there were no appreciable differences in the prevalence of hepatitis virus markers between the two studied populations with distinct living place and lifestyle. A nationwide epidemiological survey of hepatitis viruses should be conducted in an effort to prevent de novo infection with hepatitis viruses in Mongolia.

Background: The average life span of Mongolians is 62 years for males and 69 years for females. This life span is about 16 years shorter than that of Japanese. Mongolian people generally eat meat, fat and diary products but less vegetables or fruit. Thus, we investigated the state of oxidative stress and dietary habits of Mongolians.

Mongolians are known to have relatively short life expectancy. In order to examine the role of dietary habits in the early aging of Mongolians, the food intake inquiry, anthropometric measurements and blood clinical tests were performed for 365 healthy inhabitants in Murun, a northern Mongolia city, and compared to those of Japanese. Murun inhibitants were found to have a characteristic dietary habit of taking large amounts of meat, milk, dairy products and wheat flour products, in contrast little vegetables, fruits and fishes. The daily calorie intake of the adults was estimated to be 2,525 kcal, and the fat/total calorie ratio was calculated 33.7%, about 1.3-fold higher than that of Japanese. The intake ratio of fatty acid from the Mongolian foods, saturated : mono-unsaturated : poly-unsaturated fatty acids (PUFA) ratio, was 10.3 : 7.8 : 3.0. Results of blood clinical tests showed significantly higher levels of serum triglycerides, low-density lipoprotein cholesterol (LDL) and homocysteine, and lower levels of high-density lipoprotein cholesterol (HDL), n-3 PUFA, folic acid and adiponectin, in comparison with those of Japanese. In addition, the Mongolians were also found to have significantly high levels of oxidative stress markers, such as serum malondialdehyde-modified LDL (MDA-LDL), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum reactive oxygen metabolites (ROM). The serum ROM level in the Mongolians seemed to associate with their body fat ratio (p<0.05), and was significantly inverse-correlated to handgrip strength (p<0.001). Obesity was observed at a high incidence in the subjects over 30-year old, and over 40-year old their handgrip ability was markedly decreased. These findings suggest that in the Mongolians the dietary habits associate with their lifestyle-related diseases and early aging, and the improvement of dietary habits is an effective strategy for health promotion of the inhabitants.