Characteristics of studies that have assessed cognitive functioning in patients with type 1 diabetes, comparing different diabetic characteristics
| First author (ref.) | Type (grp 1/grp 2) | n (grp 1/grp 2) | % Males (grp 1/grp 2) | Age (grp 1/grp 2) | HbA1 (grp 1/grp 2) | Duration (grp 1/grp 2) | Calculated age at onset (grp 1/grp 2) | Included complications and characteristics | Exclusion criteria or absent characteristics | Subjects matched for |
|---|---|---|---|---|---|---|---|---|---|---|
| Hung et al. 1984 (33) | Poor MC/good MC | 12/20 | 67/65 | 35.1/34.15 | 13 ± 0.9/10 ± 0.8 | 20.2/22.8 | 15/14 | R,N | Ne | ND |
| Skenazy et al. 1984 (19) | Vis imp/non-vis imp | 20/19 | 70/53 | 28 ± 6.1/32.1 ± 6 | ND/ND | 18.7 ± 5.9/15.3 ± 7.8 | 9/17 | H,N,R,Ne | ND | ND |
| Holmes 1986 (7) | Poor MC/good MC | 8/19 | 100/100 | 20.9 ± 2.4/23.4 ± 5.4 | 12.4 ± 0.7/8.2 ± 1.6 | 7.8 ± 4.1/8.4 ± 5.7 | 13/15 | ND | P | E,SES |
| Holmes et al. 1988 (34) | Poor MC/good MC | 6/10 | 100/100 | 22.2 ± 4.3/24 ± 5.3 | 10.1 ± 1/6.9 ± 0.8 | 7.5 ± 3.8/6.7 ± 4.4 | 15/14 | ND | R | ND |
| Prescott et al. 1990 (35) | Poor MC/good MC | 20/20 | 50/50 | 40.3 ± 11.6/39.8 ± 10 | 13.1 ± 1.6/8.9 ± 1 | 15.2 ± 10.5/14 ± 10.3 | 25/26 | ND | ND | SES |
| Widom et al. 1990 (21) | Poor MC/good MC | 9/8 | 44/50 | 22 ± 3/27 ± 5.7 | 11.8 ± 1.2/8 ± 0.6 | 12 ± 6/7 ± 2.8 | 10/20 | R,ND | N,Ne | ND |
| Wredling et al. 1990 (4) | Sev hy/no sev hy | 17/17 | ND/ND | 49 ± 18/48 ± 17 | 7.9 ± 1.6/8.8 ± 1.6 | 28 ± 18/29 ± 13 | 21/19 | N,R,P | ND | E |
| Langan et al. 1991 (36) | Sev hy/no sev hy | 24/23 | 58/48 | 37.9 ± 6.4/38.5 ± 5.3 | 10 ± 2.3/10.2 ± 1.8 | 10.7 ± 4/13 ± 4 | 27/25 | R,N,Ne,H | CV,P,PD | ND |
| Sachon et al. 1992 (3) | IHA/NHA | 30/25 | 77/60 | 41 ± 13/34 ± 10 | 7.4 ± 1.2/8.6 ± 1.9 | 18 ± 13/15 ± 11 | 24/19 | N,Ne,R | ND | O,SES |
| Ryan et al. 1993 (27) | Compl/no compl | 113/29 | 49/55 | 34.3 ± 5.4/30.7 ± 5.6 | 10.6 ± 1.7/10.7 ± 1.9 | 25.9 ± 5.6/20.5 ± 5.8 | 8/10 | N,Ne,R | ND | E,SES |
| Chabriat et al. 1994 (37) | Sev hy/no sev hy | 15/6 | ND/ND | 47.6 ± 17/42.8 ± 19 | 7.2 ± 1.7/7.1 ± 0.8 | 19.6 ± 16/11.3 ± 7 | 28/32 | H,R,M,N,CV | E | |
| Gold et al. 1995 (38) | IHA/NHA | 10/10 | ND/ND | 35 ± 7.7/37.4 ± 5.1 | 9.7 ± 1/10.3 ± 2.2 | 12.8 ± 4.4/17.9 ± 7.8 | 23/19 | H | P,R,N | ND |
| Maran et al. 1995 (28) | Poor MC/good MC | 10/8 | 60/75 | 32 ± 4/36 ± 3 | 10.1 ± 0.2/7.7 ± 0.3 | 17 ± 3/16 ± 2 | 15/20 | ND | ND | ND |
| DCCT 1996 (39) | ||||||||||
| >5 episodes | Sev hy/no sev hy | 23/1,045 | ND/ND | <50/<50 | ND/ND | >6/>6 | ND | — | R,Ne,N,P | ND |
| 1–5 episodes | Sev hy/no sev hy | 314/1,045 | ND/ND | <50/<50 | ND/ND | >6/>6 | ND | — | R,Ne,N,P | ND |
| Reichard et al. 1996 (40) | Poor MC/good MC | 48/43 | ND | ND/ND | 8.3 ± 1/7.2 ± 0.6 | ND/ND | ND | R | ND | |
| Hershey et al. 1997 (29) | Sev hy/no sev hy | 26/12 | ND/ND | 26.2 ± 6.6/22.8 ± 7.7 | ND/ND | >5/>5 | <14 | — | R,N | E |
| Kramer et al. 1998 (30) | ||||||||||
| Hypoglycemia | Sev hy/no sev hy | 55/53 | 35/57 | 38 ± 14/34 ± 12 | 7 ± 1.6/6.9 ± 1.3 | 17.6 ± 11.6/10.8 ± 10.6 | 20/23 | H,N,R | P,Ne | A |
| MC | HbA1c >6.5/HbA1c <6.5 | ND/ND | ND/ND | ND/ND | ND/ND | ND/ND | >16 | H,N,R | P,Ne | A |
| Snoek et al. 1998 (31) | Sev hy/no sev hy | 9/9 | 36.9 ± 6.7/36.9 ± 6.7 | 7.4/7.4 | 13.4/13.4 | 24/27 | — | P | A,S | |
| Howorka et al. 2000 (41) | Sev hy/no sev hy | 13/14 | 46/36 | 36.1 ± 10.2/36.1 ± 10 | 7.6 ± 1/7.3 ± 1.2 | 16.7 ± 7.4/15.6 ± 8.6 | 19/20 | R | P,CV,N,CI | A,S |
| Strachan et al. 2000 (42) | IHA/NHA | 20/20 | 65/60 | 36.4 ± 14.7/34 ± 12.5 | 8.3 ± 1.3/10 ± 1.7 | 15.5 ± 7.6/13 ± 8.2 | 20/21 | ND | P | A,S |
| Ferguson et al. 2003 (8) | R/no R | 25/46 | 50/40 | 31.5 ± 6/26.4 ± 4.6 | 8.9 ± 1.3/8.4 ± 1.2 | 21.6 ± 5.9/17 ± 4.6 | 10/9 | Hy | N,Ne,H,P | ND |
Data are means ± SD, unless otherwise indicated. A, age; CI, cardiac insufficiency; Compl, diabetes complications; DL, dyslipidemia; E, education; Gluc, hypoglycemia prevented during testing; H, hypertension or hypertensive treatment; Hy, severe hypoglycemic episodes; IHA, impaired awareness of hypoglycemia; MC, metabolic control; N, neuropathy; ND, not specifically defined; Ne, nephropathy and/or microalbuminuria; NHA, normal awareness of hypoglycemia; O, occupation; P, psychiatric problems and/or use of psychoactive drugs and/or addiction to alcohol or other substances; R, retinopathy; S, sex; SES, socioeconomic status; Sev hy, episodes of severe hypoglycemia; Vis imp, visually impaired.