Metformin administration in prevention of colorectal polyps in type 2 diabetes mellitus patients

BACKGROUND Colorectal polyps are frequently observed in patients with type 2 diabetes mellitus(DM),posing a significant risk for colorectal cancer.Metformin,a widely prescribed biguanidine drug for type 2 DM,has been suggested to have potential chemoprophylactic effects against various cancers.AIM To explore the correlation between colorectal polyps and metformin use in type 2 DM patients.METHODS Type 2 DM patients were categorized into polyp and non-polyp groups.Following this,all patients were categorized into the type 2 DM-metformin,type 2 DM-non-metformin,and non-type 2 DM groups.Based on the baseline colonoscopy results,we performed pairwise comparisons of the incidence of colorectal polyps among the three groups.Additionally,we analyzed the relationship between colorectal polyps and the duration of metformin use and between the size and number of polyps and metformin use.Simultaneously,we focused on the specific pathological types of polyps and analyzed their relationship with metformin use.Finally,we compared the incidence of polyps between metformin and non-metformin groups according to the interval colonoscopy results.RESULTS The rate of metformin use in patients with colorectal polyps was 0.502 times that of patients without colorectal polyps[odds ratio(OR)=0.502,95%confidence interval(CI):0.365-0.689;P<0.001].The incidence of colorectal polyps did not differ significantly between the type 2 DM-metformin and non-type 2 DM groups(P>0.05).Furthermore,the correlations between the duration of metformin use and the incidence of colorectal polyps and between the size and number of polyps and metformin use were not statistically significant(P>0.05).Metformin use did not affect the incidence of colorectal polyps during interval colonoscopy(P>0.05).CONCLUSION Metformin use and colorectal polyp incidence in type 2 DM patients showed a negative correlation,independent of the hypoglycemic effect of metformin.

Non-alcoholic fatty liver disease: the problems we are facing

OBJECTIVE: To review the current state of research in non-alcoholic fatty liver disease (NAFLD). DATA RESOURCES: Searching Medline (1994-2002) and Chinese Medical Journals Index (1998- 2002) for articles on NAFLD. RESULTS: NAFLD is a new and challenging field with increasing recognition although its pathogenesis is poorly understood. 'Two hits' hypothesis is still the leading theory guiding current research. CONCLUSIONS: Genetic study is a promising way that might lead to breakthrough in NAFLD research. NAFLD study in China is at an initial stage and there is a long way to go.

Influence of Gravity on Structure of Colloidal Crystal Using Simulated Microgravity

Liquid mixtures of water and deuterium oxide as the liquid phase, were used to match the density of charged colloidal particles. Kossel diffraction method was used to detect the crystal structures. The experiments under the density-matched （g=0） and unmatched （g=1） conditions are compared to examine the influence of gravity on the crystal structures formed by self-assembly of 110 nm （in diameter） polystyrene microspheres. The result shows that the gravity tends to make the lattice constants of colloidal crystals smaller at lower positions, which indicates that the effect of gravity should be taken into account in the study of the colloidal crystals.