Impact of nonalcoholic fatty liver disease on insulin resistance in relation to HbA1c levels in nondiabetic subjects.
OBJECTIVE
A cross-sectional analysis was conducted in healthy, nondiabetic Korean adults to assess the prevalence of nonalcoholic fatty liver disease (NAFLD), to compare the prevalence of NAFLD across different glycemic ranges as assessed by glycosylated hemoglobin (HbA1c), and to examine the impact of NAFLD on insulin resistance in relation to HbA1c levels.


METHODS
After rigorous exclusion criteria, the final number of subjects who participated in a comprehensive health status checkup program was 99,969. All subjects were classified into four categories with respect to HbA1c level (≤4.9, 5.0-5.4, 5.5-5.9, and 6.0-6.4%). We estimated the odds ratio (OR) for prevalence of NAFLD according to the categorized level of HbA1C and evaluated the association of NAFLD with the homeostatic model assessment of insulin resistance (HOMA-IR) in relation to the HbA1c level.


RESULTS
Twenty-eight percent (n=28,130, 40.2% of the men, 10.3% of the women) of the study subjects had NAFLD. Men had a 5.83-fold (95% confidence interval 5.63-6.05) increased risk for having NAFLD than did women. The risk for NAFLD increased with increasing level of HbA1c (OR 1.44, 2.62, and 7.18) when compared with the lowest quartile (HbA1C≤4.9%). HOMA-IR increased in the NAFLD subjects as the level of HbA1c increased. The magnitude of association of HOMA-IR with HbA1c level was greater in NAFLD subjects than in non-NAFLD subjects (P<0.001 for interaction). These associations were consistent even after adjustment for body mass index and other metabolic components.


CONCLUSIONS
NAFLD had an association with HbA1c level and insulin resistance in nondiabetic individuals, and these associations were independent of obesity and other metabolic components.
Bae
Ji Cheol
JC
Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
Cho
Yong Kyun
YK
Lee
Won Young
WY
Seo
Hyun Il
HI
Rhee
Eun Jung
EJ
Park
Se Eun
SE
Park
Cheol Young
CY
Oh
Ki Won
KW
Sung
Ki Chul
KC
Kim
Byung Ik
BI
D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000150:complications / Q000453:epidemiology* / Q000378:metabolism; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D015995:Prevalence
D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human