Association of low-density lipoprotein cholesterol within the normal range and NAFLD in the non-obese Chinese population: a cross-sectional and longitudinal study

Abstract

ObjectivesThe relationship between normal low-density lipoprotein cholesterol (LDL-c) levels and non-alcoholic fatty liver disease (NAFLD) in non-obese individuals remains unclear. We aimed to investigate the precise prevalence and incidence of NAFLD within the normal LDL-c range in non-obese individuals.DesignCross-sectional and longitudinal study.SettingWenzhou Medical Center of Wenzhou People's Hospital from 2010 to 2014.Participants183 903 non-obese individuals were enrolled from a cross-sectional population, and a total of 16 173 initially NAFLD-free non-obese individuals were included who completed a 5-year follow-up examination in the longitudinal population.ResultsIn our study, NAFLD was defined by ultrasonographic detection of steatosis in the absence of other liver disease. The cross-sectional study showed that at baseline, the prevalence of NAFLD was 13.9% in non-obese individuals with normal LDL-c levels. The prospective study demonstrated that NAFLD-free participants developed NAFLD during the 5-year follow-up period, with a cumulative incidence of 14.4%. In addition, the ORs for NAFLD in the cross-sectional population were 1.11 (95% CI 1.04 to 1.18), 1.37 (95% CI 1.27 to 1.47) and 1.56 (95% CI 1.43 to 1.69), respectively, after adjusting for known confounding variables. The HRs for NAFLD in the longitudinal population were 1.15 (95% CI 0.98 to 1.36), 1.32 (95% CI 1.10 to 1.58) and 1.82 (95% CI 1.47 to 2.52), compared with Q1. Individuals with higher LDL-c level within the normal range had an increased cumulative incidence rate of NAFLD in non-obese individuals.ConclusionsNAFLD is prevalent in the non-obese Chinese population. Furthermore, this is the first study to demonstrate that increased normal LDL-c levels are independently associated with an elevated risk of NAFLD in non-obese individuals.

Mean Arterial Pressure Is Related to Incident Nonalcoholic Fatty Liver Disease among the Nonobese Female with Normal Low-Density Lipoprotein Cholesterol Levels: A Large Cohort Study in China

“…Although individuals with NAFLD tend to be obese, quite a few NAFLD are nonobese population [11,14], and unexpectedly, the proportion of nonobesity in NAFLD reached up to 75% in India [15]. The nonobese population with normal LDL-C levels in China had a 14.37% chance of developing NAFLD during five years of follow-up.…”

“…The raw data that we tried to analyze was downloaded freely from an online database named "DATADRYAD" (http://www.Datadryad.org), which supports the reuse of data of published studies. In the light of terms of service, we cited the data package upload by Sun et al in our present study [11,12]. We performed a secondary analysis with no need for another ethic approval because the original study protocol was vetted and approved by the ethics committee of Wenzhou People's Hospital.…”

“…Finally, a total of 16,153 participants without NAFLD at the baseline were included in our research. The process of the selection was specifically exposited in the previous report [11].…”

“…Fasting venous blood sample collection (required an overnight fast) would be measured with an automated analyzer (Abbott AxSYM). More specific details were presented in the previous reports [8,11].…”

“…For another, most previous studies paid their attention to progression of NAFLD among the obese population. And a previous study enrolled 183,903 nonobese Chinese with normal lowdensity lipoprotein cholesterol (LDL-C) levels, of which 25,503 individuals were diagnosed with NAFLD by ultrasonography [11].…”