L-carnitine supplementation in non-alcoholic fatty liver disease: A systematic review and meta-analysis

Table 1 Published studies to date evaluating the effect of L-carnitine supplementation on liver fat and/or biochemistry in non-alocholic fatty liver disease

Ref.	Study population (diagnosis); comorbidities	Sample size (M/F) Control/Carnitine	Age (yr)	BMI	Duration (wk)	Intervention (dose)	Outcome Measures	Control	Results
Malaguarnera et al[10]	Biopsy-proven NASH without diabetes	74 (40/34)	47.8 ± 5.8 (CTRL)	26.5 ± 3.8 (CTRL)	24	L-carnitine (1000 mg BD) plus hypocaloric (1600 cal ) diet	Primary: Improvement in histological features of NASH	Placebo plus Hypocaloric (1600 cal) diet	Primary Outcome: ↓ NASH activity score1 (9.42-3.19), ↓ALT1 ↓AST1, ↓GGT1 ↓TC1, ↓LDL1, ↑HDL1, ↓GLC1, ↓HOMA-IR1, ↓CRP1, ↓TNFα1
		38 (CTRL)	47.9 ± 5.4 (CAR)	26.6 ± 3.7 (CAR)			Other: ALT, AST, lipid profile, GLC, HOMA-IR, CRP, TNFα
		36 (CAR)
Bae et al[11]	NAFLD with type 2 diabetes	78 (54/24)	52 ± 9.4 (CTRL)	26.7 ± 3.7 (CTRL)	12	Carnitine orotate complex (824 mg TDS)	Primary: Change in ALT	Placebo	Primary outcome: ↓ALT (89.7% vs 17.9%)1
		39 (CTRL)	50.6 ± 9.3 (CAR)	28.2 ± 2.6 (CAR)			Other: Liver attenuation index (CT)		Other: ↓Liver attenuation index1 (0.74 ± 8.05 vs 6.21 ± 8.96)1, ↓HbA1c, ↓GLC, ↓HOMA-IR2
		39 (CAR)
Alavinejad et al[12]	NAFLD (ultrasound+ raised ALT) with T2DM	54 (38/16)	59 ± 9 (CTRL)	29.5 ± 3.6 (CTRL)	12	L-carnitine (750 mg TDS)	Primary: AST, ALT	Placebo	Primary outcome: ↓ALT1, ↓AST1 Other: ↓TG2, ↓GLC2, ↓HbA1c2
		26 (CTRL)	60 ± 5 (CAR)	28.6 ± 4.6 (CAR)			Other: TG, GLC, HbA1c
		28 (CAR)
Hong et al[13]	NAFLD (plasma ALT 40-250) and impaired glucose tolerance (HbA1C ≥ 6.0%)	52 (36/16)	52.0 ± 9.6 (CTRL)	27.0 ± 3.1 (CTRL)	12	Carnitine-orotate complex (300 mg TDS) + metformin	Primary: change from baseline ALT	Metformin alone	Primary outcome: ↓ ALT1
		26 (CTRL)	51.5 ± 9.4 (CAR)	27.2 ± 2.6 (CAR)			Other: GLC, HbA1c, m t DNA copy number, urine 8-OHdG		Other: ↓HbA1c2, ↑ plasma mtDNA copy number1, ↓GLC2, ↓urine 8-OHdG
		26 (CAR)
Somi et al[14]	NAFLD (ultrasound + plasma ALT ≥ 40)	80 (66/14)	40.7 ± 8	29.4 ± 3.9	24	L-carnitine (250 mg BD)	Primary: ALT, AST	No treatment	Primary outcome: ↓ALT1, ↓AST1
							Other: Sonographic change in liver fat, BMI		Other: ↓ liver fat on USS

NASH: Nonalcoholic steatohepatitis; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; GLC: Glucose; HOMA-IR: Homeostasis model of insulin resistance; CRP: C-reactive protein; TNFα: Tumour Necrosis Factor alpha; HbA1C: Haemoglobin A1C; T2DM: Type 2 diabetes mellitus; TG: Triglyceride; mt DNA: Mitochondrial DNA; oHdg: 8-hydroxydeoxyguanosine.

¹Denotes statistically significant results.

²Denotes non-statistically significant results.