Table 1 Study characteristics of smokers and non-smokers
Study | Country | No of participant | Intervention/control | Age/sex | Included/excluded from meta-analysis Study design | ||
|---|---|---|---|---|---|---|---|
Smoker | Non-smoker | Smoker | Non-smoker | ||||
Reynolds et al. [42] T2DM | USA | 414 | 66 | 348 | 18.6 39.4% M | 15.6 35.6% M | Included Cross sectional study |
Reynolds et al. [42]T1DM | USA | 2327 | 203 | 2124 | 18.3 50.7% M | 14.2 50.5% M | Included Cross sectional study |
Hofer et al. [43] T1DM | Austria and Germany | 27,561 | 4051 | 23,510 | 13.66 21.6% M | 13.66 78.4% M | Included Cross sectional study |
Thomas et al. [44] T2DM | China and Hong Kong | 496 | 196 | 300 | 53.5 100% M | 53 100% M | Included Cross sectional study |
Schwab et al. [45] T1DM | Germany | 92 | 19 | 73 | 15.9 100% F | 11.7 100% F | Excluded (skewed data) Cross sectional study |
Wakabayashi et al. [46] T1 and T2 DM | Japan | 2563 | 1332 | 1231 | 52.15 | 54.7 | Included Cross sectional study |
Hanesn et al. [47] T1DM | Denmark | 32 | 16 | 16 | 31 87.5% M | 31 87.5% M | Included Cross sectional study |
Nilsson et al. [48] T1DM | Sweden | 11,513 | 1646 | 9867 | 41.3 47% M | 40.8 55% M | Included Cross sectional study |
Nilsson et al. [48] T2DM | Sweden | 40,648 | 4512 | 36,136 | 61.1 61% M | 68.4 53% M | Included Cross sectional study |
Gerber et al. [49] T2DM | UK | 763 | 603 | 160 | 35.1 71.3% M | 36.1 52.1% M | Included Prospective cohort study |
Ohkuma et al. [50] T2DM | Japan | 1184 | 679 | 505 | 65.6 | 61.2 | Included Cross sectional study |