Micronutrient Intake Associated with Risk of MAFLD

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Findings from a cross-sectional study are providing clinicians with an overview of the association between micronutrient intake and risk of metabolic dysfunction-associated fatty liver disease (MAFLD).

The study, which was based on the 2017-2020 National Health and Nutrition Examination Survey (NHANES), found high copper intake and moderate iron intake may be associated with a decreased risk of MAFLD regardless of gender or the presence of diabetes or hypertension.¹

“Dietary intervention has been reported to play an important role in the management of MAFLD since there are no approved pharmacological treatment. Evidence has shown that oxidative stress, insulin resistance, and lipid metabolism disturbances are associated with the progression of fatty liver diseases,” wrote investigators.¹ “Currently, there are no studies reporting the association between micronutrients and MAFLD.”

The most common cause of chronic liver disease in the United States, MAFLD is closely associated with metabolic syndrome and its ensuing complications. Although its pathogenesis is multifaceted, it is heavily influenced by nutritional and hormonal inputs. Compared to our understanding of macronutrients’ role in this process, less is known about how micronutrients may impact MAFLD, calling for further research to better recognize potential risk factors linked to patients’ dietary habits.²

To assess the association between micronutrient intake and MAFLD, Jun-zhen Hou, of the department of gastroenterology at Shijingshan Teaching Hospital of Capital Medical University in China, and colleagues used dietary recall interview data from NHANES to assess the dietary intake of copper, zinc, iron, and selenium. The average value of a pair of 24-hour dietary recall responses was compared to the presence of MAFLD, defined by hepatic steatosis on ultrasound transient elastography examination and being considered overweight/obese, having type 2 diabetes mellitus, or having metabolic dysregulation.¹

The present study included individuals ≥18 years of age with liver ultrasound transient elastography examination and both 24-hour dietary recalls for micronutrient intake from NHANES. Those with unusually low or high total energy intake, defined as <500 or >5000 kcal/day for females and <500 or >8000 kcal/day for males, or who were missing data on key covariates were excluded.¹

Investigators identified 9693 participants from the 2017-2020 NHANES, 1376 of whom were excluded due to lack of liver ultrasound transient elastography examination and 1752 of whom did not have data for both 24-hour dietary recalls for micronutrient intake. Of the remaining 6565 patients, 89 with unusually low or high total energy intake and 500 missing information for key covariates were excluded.¹

A total of 5976 participants were included in the present study, including 3437 diagnosed with MAFLD. Among the cohort, 2918 (49.18%) participants were male and the mean age was 48.16 years.¹

Micronutrient values were divided into quartiles and used to classify participants. According to the content per 1000 kcal, copper intake was divided into Q1 (≤0.43 mg), Q2 (0.43–0.53 mg), Q3 (0.53–0.69 mg), and Q4 (>0.69 mg). Zinc intake was divided into Q1 (≤3.98 mg), Q2 (3.98–4.82 mg), Q3 (4.82–5.94 mg), and Q4 (>5.94 mg). Iron intake was divided into Q1 (≤5.19 mg), Q2 (5.19–6.19 mg), Q3 (6.19–7.57 mg), and Q4 (>7.57 mg). Selenium intake was divided into Q1 (≤43.09 mcg), Q2 (43.09–53.02 mcg), Q3 (53.02–64.31 mcg), and Q4 (>64.31 mcg).¹

In an unadjusted model, investigators found copper intake in Q4 (Odds ratio [OR], 0.71; 95% Confidence interval [CI], 0.55,-0.91) and iron intake in Q3 (OR, 0.70; 95% CI, 0.53-0.92) was associated with the decreased odds of MAFLD compared to the reference group. After adjusting for age, gender, race, BMI, WHtR, diabetes, hypertension, dyslipidemia, ALT, BUN, GGT, and uric acid, participants with copper intake in Q3 and Q4 (OR, 0.67; 95% CI, 0.49-0.91 and OR, 0.58; 95% CI, 0.43-0.78, respectively) and iron intake in Q2 and Q3 (OR, 0.63; 95% CI, 0.44-0.91 and OR, 0.59; 95% CI, 0.40-0.85, respectively) were found to be associated with decreased odds of MAFLD compared to participants in Q1.¹

Investigators pointed out similar results were observed after further adjusting copper, zinc, iron, and selenium intake (copper intake in Q3 OR, 0.68; 95% CI, 0.50-0.93; copper intake in Q4 OR, 0.60; 95% CI, 0.45-0.80; iron intake in Q2 OR, 0.64; 95% CI, 0.45-0.92; iron intake in Q3 OR, 0.61; 95% CI, 0.41-0.91). The same was true in hepatitis, BMI, dyslipidemia, and hypertension subgroups. No statistically significant difference was found in the association between zinc intake and selenium intake and the odds of MAFLD (all P > 0.05).¹

“Our findings may indicate the importance of micronutrients in MAFLD and provide guidance for the management of MAFLD. Future prospective studies should be performed to confirm these findings,” investigators concluded.¹

References:

1. Hou J, Wu Q, Zhang L. Association between micronutrients intake and metabolic-associated fatty liver disease: a cross-sectional study based on the National Health and Nutrition Examination Survey. Journal of Nutritional Science. doi:10.1017/jns.2023.99
2. Gillespie J. "You Are What You Eat": The Role of Dietary Macronutrients and Micronutrients in MAFLD. Clin Liver Dis (Hoboken). 2021;18(2):67-71. Published 2021 Sep 12. doi:10.1002/cld.1083