Identification of reciprocal causality between non-alcoholic fatty liver disease and metabolic syndrome by a simplified Bayesian network in a Chinese population

Abstract

ObjectivesIt remains unclear whether non-alcoholic fatty liver disease (NAFLD) is a cause or a consequence of metabolic syndrome (MetS). We proposed a simplified Bayesian network (BN) and attempted to confirm their reciprocal causality.SettingBidirectional longitudinal cohorts (subcohorts A and B) were designed and followed up from 2005 to 2011 based on a large-scale health check-up in a Chinese population.ParticipantsSubcohort A (from NAFLD to MetS, n=8426) included the participants with or without NAFLD at baseline to follow-up the incidence of MetS, while subcohort B (from MetS to NAFLD, n=16 110) included the participants with or without MetS at baseline to follow-up the incidence of NAFLD.ResultsIncidence densities were 2.47 and 17.39 per 100 person-years in subcohorts A and B, respectively. Generalised estimating equation analyses demonstrated that NAFLD was a potential causal factor for MetS (relative risk, RR, 95% CI 5.23, 3.50 to 7.81), while MetS was also a factor for NAFLD (2.55, 2.23 to 2.92). A BN with 5 simplification strategies was used for the reciprocal causal inference. The BN's causal inference illustrated that the total effect of NAFLD on MetS (attributable risks, AR%) was 2.49%, while it was 19.92% for MetS on NAFLD. The total effect of NAFLD on MetS components was different, with dyslipidemia having the greatest (AR%, 10.15%), followed by obesity (7.63%), diabetes (3.90%) and hypertension (3.51%). Similar patterns were inferred for MetS components on NAFLD, with obesity having the greatest (16.37%) effect, followed by diabetes (10.85%), dyslipidemia (10.74%) and hypertension (7.36%). Furthermore, the most important causal pathway from NAFLD to MetS was that NAFLD led to elevated GGT, then to MetS components, while the dominant causal pathway from MetS to NAFLD began with dyslipidaemia.ConclusionsThe findings suggest a reciprocal causality between NAFLD and MetS, and the effect of MetS on NAFLD is significantly greater than that of NAFLD on MetS.

Bidirectional association between nonalcoholic fatty liver disease and type 2 diabetes in Chinese population: Evidence from the Dongfeng-Tongji cohort study

“…Growing evidence suggested that there was bidirectional association between NAFLD with MetS and T2DM [14–16]. A series of prospective studies showed that NAFLD strongly increased MetS and T2DM incident risk [7,33].…”

“…Although growing evidence suggested that the NAFLD-T2DM relation is bidirectional [13–15], few studies simultaneously investigated the bidirectional association between NAFLD and T2DM in a prospective setting [16]. Therefore, in the present study, we aimed to address the bidirectional relationship between NAFLD and T2DM in a prospective cohort study among a middle-aged and elderly Chinese population.…”

Proteinuria and risk of stroke in patients with hypertension: The Kailuan cohort study

“…6,19 A recent study from the China Stroke Primary Prevention Trial also found that baseline proteinuria as measured by dipstick was an independent risk factor for first incident stroke and ischemic stroke. 20 A meta-analysis of cohort studies or randomized controlled trials also concluded that increasing albuminuria increased the risk of stroke. 21 Findings from the current study extend those from previous studies.…”

Clinical risk scoring for predicting non‐alcoholic fatty liver disease in metabolic syndrome patients (NAFLD‐MS score)

“…However, we did not have the data of liver biopsy as the gold standard for diagnosis in this cohort. Fourthly, the inherent limitation of non‐invasive indices by using parameters belonging to the domain of MetS is that they might fail to take into account the dynamic and bidirectional relationship linking NAFLD with MetS . Some individuals who have fatty liver now may develop MetS feature later .…”

“…Fourthly, the inherent limitation of non-invasive indices by using parameters belonging to the domain of MetS is that they might fail to take into account the dynamic and bidirectional relationship linking NAFLD with MetS. [59][60][61][62] Some individuals who have fatty liver now may develop MetS feature later. 30 On the contrary, as amount of steatosis decrease with advance fibrosis, some patients with NAFLD may be misdiagnosed.…”