Table 4. Subgroup analyses on different tissue n-3 polyunsaturated fatty acid compositions in subjects with and without type 2 diabetes.

N-3 PUFAs	No. of studies	SMD (95% CI)	P-heterogeneity	I 2 (%)
C22∶6n-3	12	−0.31 (−0.70, 0.07)	<0.001	96.4
Asian countries	4	−1.43 (−1.75, −1.12)	0.051	61.3
Western countries	8	0.16 (−0.05, 0.37)	<0.001	82.8
C20∶5n-3	10	−0.16 (−0.53, 0.21)	<0.001	96.3
Asian countries	4	−0.69 (−1.96, 0.59)	<0.001	97.9
Western countries	6	0.09 (−0.03, 0.20)	0.055	51.3
C18∶3n-3	10	−0.48 (−0.86, −0.11)	<0.001	96.5
Asian countries	3	−0.92 (−2.27, 0.42)	<0.001	98.0
Western countries	7	−0.27 (−0.50, −0.05)	<0.001	87.2
Total n-3 PUFA	8	−0.56 (−1.22, 0.09)	<0.001	98.0
Asian countries	4	−1.41 (−2.23, −0.59)	<0.001	96.7
Western countries	4	0.18 (0.08, 0.28)	0.638	0

Abbreviations: n-3 PUFAs: n-3 polyunsaturated fatty acids; SMD: standardized mean difference.