Table 1.
Sample characteristics of dementia-free participants from the Gothenburg H70 Birth Cohort Study.
| Total sample N = 674 |
Women N = 362 |
Men N = 312 |
p-value | |
|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | ||
| Age (years) | 70.8 (0.3) | 70.8 (0.3) | 70.8 (0.3) | 0.88 |
| Predicted brain age (years) | 71.5 (1.8) | 71.4 (1.7) | 71.5 (1.9) | 0.99 |
| Total body fat (%) | 36.3 (8.0) | 40.5 (6.9) | 31.4 (6.2) | <0.0001 |
| Total mean cortical thickness (mm) | 2.35 (0.08) | 2.35 (0.07) | 2.35 (0.08) | 0.032 |
| AD-signature cortical thicknessb (mm) | 2.72 (0.09) | 2.72 (0.09) | 2.73 (0.10) | 0.52 |
| Hippocampal volume (adjusted for total intracranial volume, mm3) | 3931 (320) | 3923 (290) | 3941 (351) | 0.47 |
| Handgrip strength (kPa) | 78.6 (16.1) | 73.2 (14.0) | 84.8 (16.2) | <0.0001 |
| Gait speed (meter/second) | 1.31 (0.17) | 1.31 (0.17) | 1.32 (0.17) | 0.27 |
| BMI (kg/m2) | 26.2 (4.3) | 26.1 (4.8) | 26.3 (3.7) | 0.66 |
| ALSTIc | 7.17 (1.04) | 6.56 (0.78) | 7.87 (0.84) | <0.0001 |
| Median (IQR) | Median (IQR) | Median (IQR) | ||
|---|---|---|---|---|
| MMSE score (0–30) | 29 (29, 30) | 30 (29, 30) | 29 (29, 30) | 0.068 |
| Global cognitive composite scorec (z-score) | 0.13 (−0.30, 0.54) | 0.20 (−0.20, 0.57) | 0.04 (−0.40, 0.51) | 0.0039 |
| Visceral adipose tissue (kg) | 1.2 (0.6, 1.9) | 0.8 (0.4, 1.3) | 1.7 (1.1, 2.2) | <0.0001 |
| Brain age gapa (years) | 0.30 (−0.60, 1.40) | 0.45 (−0.60, 1.50) | 0.30 (−0.50, 1.4) | 0.55 |
| N (%) | N (%) | N (%) | ||
|---|---|---|---|---|
| Sarcopenic level muscle massd (ALSTI <7.0 men, <5.5 women) | 61 (9) | 21 (6) | 40 (13) | 0.0016 |
| Probable sarcopenia (Handgrip strength <69 men, <59 women) | 94 (14) | 51 (14) | 43 (14) | 0.90 |
| Sarcopenia (low muscle mass and low handgrip strength) | 16 (2.3) | 5 (1.2) | 11 (3.5) | 0.069 |
| Cerebral small vessel disease score (0–3)e | 0.0026 | |||
| 0 | 265 (40) | 125 (35) | 140 (45) | |
| 1 | 263 (39) | 164 (46) | 99 (32) | |
| 2 | 107 (16) | 56 (16) | 51 (17) | |
| 3 | 35 (5) | 15 (4) | 20 (7) | |
| Physical activity (Regular physical activity) | 589 (87) | 315 (87) | 274 (88) | 0.75 |
| Education | <0.0001 | |||
| Compulsory primary education | 52 (8) | 21 (6) | 31 (10) | |
| Secondary education | 293 (44) | 188 (52) | 105 (34) | |
| Higher education | 329 (49) | 153 (42) | 176 (56) | |
| Smokingc (Non-smoking) | 632 (94) | 335 (93) | 297 (95) | 0.16 |
Note: Educational level was divided into three categories based on Swedish education classifications: compulsory primary education (pre-primary education, primary and lower secondary education less than 9 years), secondary education (primary and lower secondary education 9 years, upper secondary education, and post-secondary education less than 2 years), and higher education (post-secondary education 2 years or longer, and postgraduate education). Smoking was defined as either smoking (current smoker) or non-smoking (previous smoker or never smoked). Physical activity was dichotomized into inactive/light physical activity or regular physical activity. BMI was measured as kg body weight/body height meter2. There were missing cerebral small vessel disease (CSVD) data for 4 participants, missing MMSE (Mini-Mental State Examination) data for 2 participants, missing gait speed data for 10 participants, missing visceral adipose tissue (VAT) data for 3 participants, and missing hand grip strength data for 1 participant.
Brain age gap (BAG) is the difference between chronological age and predicted brain age. A negative value indicates a biologically younger brain, and a positive value a biological older brain, compared to chronological age.
AD-signature: Averaging cortical thicknesses of entorhinal, inferior temporal, middle temporal, and fusiform regions, adjusted for surface area.
The global cognitive composite score was derived from eight cognitive tests covering five cognitive domains: executive function, perceptual speed, verbal fluency, episodic memory, and visuospatial abilities.
Appendicular lean soft tissue index (ALSTI, kg/body height m2) is used as a marker of muscle mass. Sarcopenic level muscle mass: below the EWGSOP2 sarcopenia cut-off of ALSTI <7.0 men, <5.5 women.
The global cerebral small vessel disease score ranged from 0 (no cerebrovascular burden)—3 (high cerebrovascular burden), including measures of white matter hyperintensities, cerebral microbleeds, enlarged perivascular spaces in basal ganglia, and lacunes.