Introduction
Participants and methods
Participants and procedures
Assessment of subjective memory concerns (SMC)
Assessment of objective cognitive function
Other measures
Statistical analyses
Results
Characteristics | Subjective memory concerns wave 1 and 2 | |||
---|---|---|---|---|
No | Remitting | New-onset | Sustained | |
n = 1013 | n = 77 | n = 77 | n = 69 | |
Demographic at wave 1 | ||||
Female, n (%) | 487 (48.1) | 36 (46.8) | 33 (42.9) | 24 (34.8) |
Age, years, mean ± SD | 62.5 ± 1.5 | 62.4 ± 1.4 | 62.3 ± 1.6 | 62.5 ± 1.5 |
Education, years, mean ± SD | 14.2 ± 2.5 | 14.7 ± 2.7 | 14.4 ± 2.8 | 14.4 ± 3.1 |
Caucasian (versus Asian and other), n (%) | 987 (97.4) | 73 (94.8) | 77 (100) | 67 (97.1) |
English-speaking, n (%) | 927 (91.5) | 69 (89.6) | 72 (93.5) | 63 (91.3) |
Dementia risk factors at wave 1 | ||||
Body mass index, kilogram/meters2, median (IQR) | 26 (23.8, 28.7) | 27.3 (24, 30.1) | 26.3 (23.8, 29.1) | 26.5 (24.1, 29.1) |
Diabetes (self-reported), n (%) | 62 (6.1) | 3 (3.9) | 7 (9.1) | 3 (4.4) |
Hypertension (SBP > 140 mmHg or DBP > 90 mmHg, on or off antihypertensives), n (%) | 509 (50.3) | 43 (55.8) | 47 (61) | 29 (42) |
SBP, mmHg, mean ± SD | 139.6 ± 19 | 139.5 ± 17.4 | 141.4 ± 18.8 | 131.9 ± 18.9 |
DBP, mmHg, mean ± SD | 82.9 ± 10.3 | 83.8 ± 9.9 | 84.7 ± 10.9 | 80.8 ± 10.5 |
Traumatic brain injury (self-reported), n (%) | 43 (4.2) | 6 (7.8) | 3 (3.9) | 3 (4.4) |
Score > 2, Goldberg depression scale, n (%) | 150 (14.8) | 33 (42.9) | 29 (37.7) | 32 (46.4) |
Score > 5, Goldberg anxiety scale, n (%) | 72 (7.1) | 15 (19.5) | 10 (13) | 17 (24.6) |
Smoking (past or current versus never), n (%) | 446 (44) | 31 (40.3) | 30 (39) | 31 (44.9) |
Physical activities | ||||
Mild, less frequent than “three times a week or more”, n (%) | 261 (25.8) | 28 (36.4) | 27 (35.1) | 21 (30.4) |
Moderate, less frequent than “once or twice a week”, n (%) | 273 (27) | 31 (40.3) | 23 (29.9) | 32 (46.4) |
Vigorous, less frequent than “one to three times a month”, n (%) | 556 (54.9) | 56 (72.7) | 43 (55.8) | 49 (71) |
Cognitive performance at wave 2 or changes between waves* | ||||
Mini-Mental State Examination, median (IQR) | 30 (29, 30) | 30 (29, 30) | 30 (29, 30) | 30 (29, 30) |
Change in scores from wave 2 to 3 | 0 (− 1, 0) | 0 (− 1, 0) | 0 (− 1, 0) | 0 (− 1, 0) |
Change in scores from wave 3 to 4 | 0 (− 1, 0) | 0 (− 1, 0) | 0 (− 1, 1) | 0 (− 1, 0) |
California Verbal Learning Test immediate recall, mean ± SD | 7.3 ± 2.2 | 6.8 ± 2.2 | 6.6 ± 2.1 | 6.9 ± 2.1 |
Change in scores from wave 2 to 3 | − 0.4 ± 2 | − 0.4 ± 2.2 | 0 ± 2.3 | − 0.7 ± 1.9 |
Change in scores from wave 3 to 4 | − 1.5 ± 2.1 | − 1.3 ± 1.9 | − 1.4 ± 2.1 | − 1.2 ± 2.3 |
California Verbal Learning Test delayed recall, mean ± SD | 6.4 ± 2.3 | 6.1 ± 2.2 | 6 ± 2.3 | 6 ± 2.3 |
Change in scores from wave 2 to 3 | − 0.3 ± 2.1 | − 0.4 ± 1.8 | 0 ± 2 | − 0.7 ± 1.9 |
Symbol Digit Modalities, mean ± SD | 51.2 ± 8.9 | 50.1 ± 9.1 | 50.4 ± 8.2 | 48.5 ± 7.4 |
Change in scores from wave 2 to 3 | − 1.9 ± 5.8 | − 2.5 ± 5.2 | − 1.6 ± 4.8 | − 1.6 ± 6 |
Change in scores from wave 3 to 4 | − 2.4 ± 6.3 | − 3.2 ± 6.6 | − 2.4 ± 5.4 | − 1.9 ± 5.6 |
Trail making test part A time, seconds, median (IQR) | 32 (26, 38) | 36 (28, 44) | 33 (28, 40) | 32 (27, 40) |
Change in time from wave 2 to 3 | 2 (− 4, 8) | 0 (− 7, 7) | 1 (− 5, 7) | 0 (− 4, 7) |
Change in time from wave 3 to 4 | 1 (− 4, 7) | 3 (− 3, 10) | 0 (− 4, 6) | 2 (− 2, 9) |
Trail making test part B time, seconds, median (IQR) | 70 (58, 88) | 76 (58, 89) | 74 (60, 88) | 75 (58, 87) |
Change in time from wave 2 to 3 | 5 (− 7, 17) | 3 (− 6, 13) | 4 (− 6, 18) | 6 (− 8, 20) |
Change in time from wave 3 to 4 | 6 (− 7, 20) | 9 (− 6, 34) | 8 (− 12, 23) | 8 (− 8, 33) |
Digit span backwards, mean ± SD | 5.4 ± 2.2 | 5.8 ± 2.3 | 5.2 ± 2 | 5 ± 2.3 |
Change in scores from wave 2 to 3 | − 0.2 ± 1.8 | 0 ± 1.7 | 0.1 ± 1.9 | − 0.1 ± 1.8 |
Change in scores from wave 3 to 4 | 0 ± 1.8 | − 0.5 ± 2.1 | 0 ± 1.9 | − 0.1 ± 1.9 |
Purdue pegboard dominant hand, mean ± SD | 13.7 ± 1.9 | 13.3 ± 2.2 | 13.3 ± 2.2 | 13.4 ± 1.7 |
Change in scores from wave 2 to 3 | − 1.2 ± 1.9 | − 1.2 ± 1.8 | − 1.2 ± 2 | − 1.6 ± 1.8 |
Change in scores from wave 3 to 4 | − 0.6 ± 2.1 | − 0.5 ± 2 | − 0.8 ± 1.7 | − 0.3 ± 1.9 |
Purdue pegboard non-dominant hand, mean ± SD | 12.9 ± 1.8 | 12.4 ± 1.8 | 12.9 ± 2.1 | 12.1 ± 1.8 |
Change in scores from wave 2 to 3 | − 1.1 ± 1.9 | − 1.1 ± 2.1 | − 1.4 ± 1.7 | − 0.7 ± 1.8 |
Change in scores from wave 3 to 4 | − 0.5 ± 2.1 | − 0.5 ± 1.7 | − 0.7 ± 1.9 | − 0.7 ± 2.2 |
Purdue pegboard both hands, mean ± SD | 10.6 ± 1.7 | 10.3 ± 1.8 | 10.3 ± 2.2 | 10.2 ± 1.7 |
Change in scores from wave 2 to 3 | − 1 ± 1.6 | − 0.8 ± 1.6 | − 1.1 ± 1.6 | − 0.7 ± 1.7 |
Change in scores from wave 3 to 4 | − 0.4 ± 1.9 | − 0.8 ± 1.7 | − 0.3 ± 1.6 | − 0.9 ± 1.6 |
SMC and contemporaneous cognitive performance at wave 2 (Table 2 , column a)
Differences in | ||||
---|---|---|---|---|
Cognitive performance at wave 2 (column a) | Cognitive change between waves over the subsequent 8 years (column b) | |||
β2b (95% CI) | P value | β3b (95% CI) | P value | |
CVLT immediate recall |
0.02*
| 0.24 | ||
“Remitting” vs “no” | −0.23 (−0.43, −0.02)* |
0.03*
| 0.03 (−0.08, 0.15) | 0.59 |
“New-onset” vs “no” |
−0.25 (−0.45, −0.04)*
|
0.02*
|
0.12 (0, 0.23)*
|
0.05*
|
“Sustained” vs “no” | −0.12 (−0.33, 0.1) | 0.29 | −0.01 (−0.13, 0.11) | 0.90 |
CVLT delayed recall | 0.36 | 0.20 | ||
“Remitting” vs “no” | −0.14 (−0.36, 0.08) | 0.23 | −0.04 (−0.24, 0.17) | 0.72 |
“New-onset” vs “no” | −0.15 (−0.37, 0.07) | 0.19 | 0.11 (−0.09, 0.32) | 0.28 |
“Sustained” vs “no” | −0.09 (−0.32, 0.15) | 0.47 | −0.19 (−0.41, 0.02) | 0.08 |
Symbol Digit Modalities | 0.10 | 0.15 | ||
“Remitting” vs “no” | −0.13 (−0.36, 0.09) | 0.24 | −0.08 (−0.16, 0) | 0.06 |
“New-onset” vs “no” | −0.07 (−0.29, 0.16) | 0.56 | 0.02 (−0.06, 0.1) | 0.68 |
“Sustained” vs “no” |
−0.28 (−0.51, −0.04)*
|
0.02*
| 0.05 (−0.04, 0.14) | 0.27 |
Trails A |
0.04*
| 0.27 | ||
“Remitting” vs “no” |
1.08 (1.01, 1.15)*
|
0.02*
| 0.99 (0.96, 1.02) | 0.57 |
“New-onset” vs “no” | 1.06 (1, 1.14) | 0.06 | 0.97 (0.94, 1) | 0.08 |
“Sustained” vs “no” | 1 (0.93, 1.07) | 0.97 | 1.01 (0.98, 1.05) | 0.51 |
Trails B | 0.73 | 0.94 | ||
“Remitting” vs “no” | 1.01 (0.93, 1.09) | 0.81 | 1.01 (0.97, 1.04) | 0.79 |
“New-onset” vs “no” | 1.03 (0.95, 1.11) | 0.47 | 1 (0.97, 1.04) | 0.82 |
“Sustained” vs “no” | 1.04 (0.96, 1.13) | 0.35 | 0.99 (0.95, 1.03) | 0.61 |
Digit span backwards |
0.05*
| 0.36 | ||
“Remitting” vs “no” | 0.2 (−0.02, 0.41) | 0.07 | −0.04 (−0.14, 0.05) | 0.37 |
“New-onset” vs “no” | −0.12 (−0.33, 0.1) | 0.29 | 0.07 (−0.02, 0.17) | 0.14 |
“Sustained” vs “no” | −0.19 (−0.42, 0.04) | 0.10 | 0.01 (−0.1, 0.11) | 0.91 |
Purdue pegboard (dominant) | 0.31 | 0.70 | ||
“Remitting” vs “no” | −0.17 (−0.39, 0.05) | 0.13 | 0.03 (−0.09, 0.15) | 0.58 |
“New-onset” vs “no” | −0.11 (−0.33, 0.11) | 0.31 | −0.06 (−0.18, 0.06) | 0.33 |
“Sustained” vs “no” | −0.11 (−0.34, 0.13) | 0.37 | −0.02 (−0.14, 0.11) | 0.76 |
Purdue pegboard (non-dominant) |
0.01*
| 0.15 | ||
“Remitting” vs “no” |
−0.26 (−0.49, −0.03)*
|
0.03*
| −0.02 (−0.15, 0.11) | 0.74 |
“New-onset” vs “no” | 0.01 (−0.22, 0.24) | 0.92 |
−0.15 (−0.27, −0.02)*
|
0.03*
|
“Sustained” vs “no” |
−0.34 (−0.58, −0.09)*
|
0.007*
| 0.03 (−0.11, 0.16) | 0.67 |
Purdue pegboard (both) | 0.56 | 0.68 | ||
“Remitting” vs “no” | −0.1 (−0.33, 0.13) | 0.39 | −0.05 (−0.17, 0.07) | 0.45 |
“New-onset” vs “no” | −0.13 (−0.36, 0.1) | 0.27 | 0.03 (−0.09, 0.15) | 0.60 |
“Sustained” vs “no” | −0.08 (−0.32, 0.16) | 0.52 | −0.05 (−0.17, 0.08) | 0.44 |