Table 2. Characteristics of included studies in the meta-analysis of different n-3 polyunsaturated fatty acids compositions between subjects with and without type 2 diabetes.
| Study source | Mean age(years) | Study design | No. of cases | No. of controls | Tissue n-3 PUFAs composition (% of totalfatty acids, case vs controls) |
| Faas et al, 1988 (20) | 48.5 | Case-control | 5 | 5 | Plasma C22∶6n-3 (1.6±0.7 vs 1.5±0.5) |
| Red blood cell C22∶6n-3 (4.4±1.1 vs 4.4±1.1) | |||||
| Bohov et al, 1993 (21) | 60.6 | Case-control | 183 | 114 | Serum C22∶6n-3 (1.96±0.05 vs 1.67±0.06) |
| Serum C20∶5n-3 (0.66±0.03 vs 0.62±0.03) | |||||
| Serum C18∶3n-3 (0.42±0.01 vs 0.55±0.01) | |||||
| Serum n-3 PUFA (3.53±0.08 vs 3.31±0.09) | |||||
| Pelikanova et al, 2001 (22) | 40.4 | Case-control | 21 | 24 | Serum PL C22∶6n-3 (3.04±0.87 vs 2.11±0.49) |
| Serum PL C20∶5n-3 (1.04±0.54 vs 0.82±0.41) | |||||
| Serum PL C18∶3n-3 (0.20±0.19 vs 0.29±0.14) | |||||
| Serum PL n-3 PUFA (5.40±1.75 vs 4.67±1.39) | |||||
| Rodriguez et al, 2004 (19) | 53 | Case-control | 13 | 13 | Plasma PL C22∶6n-3 (4.01±0.80 vs 3.47±0.89) |
| Plasma PL C20∶5n-3 (0.64±0.23 vs 0.74±0.35) | |||||
| Plasma PL C18∶3n-3 (0.18±0.13 vs 0.20±0.13) | |||||
| Plasma PL n-3 PUFA (5.96±0.73 vs 5.49±1.17) | |||||
| Red blood cell PL C22∶6n-3 (3.9±1.35 vs 3.91±0.71) | |||||
| Red blood cell PL C20∶5n-3 (0.52±0.23 vs 0.44±0.12) | |||||
| Red blood cell PL C18∶3n-3 (0.15±0.04 vs 0.15±0.06) | |||||
| Red blood cell PL n-3 PUFA (7.18±1.71 vs 5.94±1.15) | |||||
| Bakan et al, 2006 (34) | 56.5 | Case-control | 32 | 20 | Plasma C22∶6n-3 (1.9±0.9 vs 2.7±0.4) |
| Mao et al, 2007 (30) | 57.4 | Case-control | 62 | 53 | Serum PL C22∶6n-3 (5.1±1.3 vs 6.4±1.1) |
| Serum PL C20∶5n-3 (1.9±0.6 vs 1.9±0.5) | |||||
| Serum PL C18∶3n-3 (0.32±0.2 vs 0.33±0.13) | |||||
| Serum PL n-3 PUFA (8.2±1.6 vs 9.6±1.5) | |||||
| Krachler et al, 2008 (17) | 51.6 | Case-control | 159 | 291 | Erythrocyte membrane C22∶6n-3 (4.61±1.01 vs 4.83±1.02) |
| Erythrocyte membrane C20∶5n-3 (1.31±0.45 vs 1.37±0.46) | |||||
| Erythrocyte membrane C18∶3n-3 (0.35±0.10 vs 0.36±0.13) | |||||
| Lou et al, 2010 (31) | 56.1 | Case-control | 60 | 55 | Serum PL C22∶6n-3 (4.11±1.32 vs 6.41±1.26) |
| Serum PL C20∶5n-3 (1.80±0.55 vs 1.90±0.52) | |||||
| Serum PL C18∶3n-3 (0.28±0.08 vs 0.33±0.10) | |||||
| Serum PL n-3 PUFA (6.08±1.66 vs 9.54±1.54) | |||||
| Huang et al, 2010 (16) | 60 | Case-control | 180 | 186 | Plasma PL C22∶6n-3 (2.46±2.2 vs 5.8±2.0) |
| Plasma PL C20∶5n-3 (0.99±0.5 vs 2.12±0.7) | |||||
| Plasma PL C18∶3n-3 (0.36±0.1 vs 0.70±0.2) | |||||
| Plasma PL n-3 PUFA (4.52±2.8 vs 9.22±1.8) | |||||
| Zhang et al, 2011 (32) | 49.2 | Case-control | 241 | 156 | Plasma total n-3 PUFA (5.52±0.77 vs 6.47±2.27) |
| Vessby et al, 1994 (33) | 50 | Prospective cohort | 75 | 1753 | Serum CE C22∶6n-3 (0.68±0.21 vs 0.70±0.21) |
| Serum CE C20∶5n-3 (1.42±0.57 vs 1.35±0.63) | |||||
| Serum CE C18∶3n-3 (0.65±0.18 vs 0.66±0.16) | |||||
| Wang et al, 2003 (18) | 52 | Prospective cohort | 252 | 2657 | Plasma PL C22∶6n-3 (2.71±0.83 vs 2.76±0.84) |
| Plasma PL C20∶5n-3 (0.58±0.33 vs 0.56±0.31) | |||||
| Plasma PL C18∶3n-3 (0.13±0.05 vs 0.15±0.05) | |||||
| Plasma CE C22∶6n-3 (0.43±0.15 vs 0.43±0.15) | |||||
| Plasma CE C20∶5n-3 (0.59±0.36 vs 0.54±0.28) | |||||
| Plasma CE C18∶3n-3 (0.4±0.11 vs 0.42±0.11) | |||||
| Hodge et al, 2007 (5) | 56.2 | Prospective cohort | 346 | 3391 | Plasma PL C22∶6n-3 (4.15±0.99 vs 4.02±1.07) |
| Plasma PL C20∶5n-3 (1.15±0.50 vs 1.05±0.47) | |||||
| Plasma PL C18∶3n-3 (0.17±0.08 vs 0.17±0.08) | |||||
| Plasma PL n-3 PUFA (6.77±1.36 vs 6.55±1.40) |
Abbreviations: n-3 PUFAs: n-3 polyunsaturated fatty acids; PL: phospholipids; CE: cholesterol esters.