Association between n-3 polyunsaturated fatty acids in erythrocytes and metabolic syndrome in Chinese men and women.

Purpose: Evidence of an association between n-3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MS) is limited and inconsistent. We investigated the association between n-3 PUFAs in erythrocytes and the presence of MS in Chinese adults.
Methods: The levels of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in erythrocytes were measured using gas chromatography in 3072 participants (900 men and 2172 women) aged 30-75 years from Guangzhou, China. Cardiometabolic factors were determined, and MS was defined using the updated Adult Treatment Panel III criteria. Other covariates were collected via interviewer-administered questionnaires.
Results: After adjusting for age and other confounders, higher levels of marine-derived n-3 PUFAs, including EPA, DPA, and DHA, were associated with a lower presence of metabolic syndrome in both men and women. The odds ratios (95 % confidence interval) for MS obtained by comparing extreme quartiles were 0.55 (0.35-0.88) (EPA), 0.54 (0.34-0.87) (DPA), 0.45 (0.27-0.73) (DHA), and 0.52 (0.32-0.84) (total n-3 PUFAs) in men (p trend <0.05 for all results); and 0.74 (0.56-0.99) (EPA), 0.73 (0.55-0.98) (DPA), 0.75 (0.56-1.02) (DHA), and 0.71 (0.53-0.96) (total n-3 PUFAs) in women, respectively. No significant association of ALA with MS was observed (p trend > 0.05).
Conclusion: Higher levels of total n-3 PUFAs, EPA, DPA, and DHA, but not of ALA, in erythrocyte membranes are associated with a lower presence of metabolic syndrome in Chinese adults.