Weight reduction is associated with improvement of glycemic control in Japanese men, whose hemoglobin A 1 C is 5.6–6.4%, with visceral fat accumulation, but not without visceral fat accumulation

Aims/Introduction The aim of the present study was to determine whether weight reduction is associated with improvement of glycemic control in non‐obese and obese subjects with or without visceral fat accumulation, whose hemoglobin A1c ( A 1 C ) is 5.6–6.4%. Materials and Methods A total of 798 male subjects whose A 1 C levels were between 5.6% and 6.4% were divided into subgroups based on body mass index ( BMI ) and/or estimated visceral fat area (e VFA ), and were analyzed with respect to the relationships between 1‐year changes in BMI (Δ BMI ) and A 1 C (Δ A 1 C ). Results In both the BMI ≥25 and BMI <25 groups, Δ A 1 C correlated positively with Δ BMI ( BMI ≥25 ( n  = 321): r  = 0.236, P  < 0.0001; BMI <25 ( n  = 477): r  = 0.095, P  = 0.0387) although the r ‐value was very small for the latter group. In addition, for the group with e VFA ≥100 cm 2 ( n  = 436), Δ A 1 C correlated positively with Δe VFA ( r  = 0.150, P  = 0.0017), but this correlation was not found for the e VFA <100 cm 2 group ( n  = 339, P  = 0.3505). Furthermore, Δ A 1 C positively correlated with Δ BMI for the groups in BMI ≥25 with e VFA >100 cm 2 ( n  = 293, r  = 0.256, P  < 0.0001) and BMI <25 with e VFA ≥100 cm 2 ( n  = 145, r  = 0.250, P  = 0.0024), but not for the groups in BMI ≥25 with e VFA <100 cm 2 ( n  = 28, P  = 0.6401) nor BMI <25 with e VFA <100 cm 2 ( n  = 332, P  = 0.6605). Conclusions These results suggest that the assessment of visceral fat, rather than BMI , might be more important in identifying subjects in whom lifestyle intervention aiming at weight reduction could be effective to prevent diabetes. This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (no. UMIN 2391).