Table 1.
Characteristics of study sample at baseline, by baseline BMI category.
| baseline BMIf (n=1,141) | |||||
|---|---|---|---|---|---|
| Variablea | Low (n=53) | Moderate (n=697) | High (n=391) | P-value | All |
| Age, mean (SD) | 80.1 (7.8) | 78.1 (6.9) | 76.6*** (6.7) | <0.001 | 77.7 (7.0) |
| Male, N (%) | 7*** (13) | 306 (44) | 181 (46) | <0.001 | 494 (43) |
| Years of education, mean (SD) | 15.4 (3.3) | 15.5 (3.0) | 15.1 (3.1) | 0.157 | 15.4 (3.1) |
| Marital status | 0.003 | ||||
| Married, N (%) | 23 (43) | 455 (65) | 230 (59) | 708 (62) | |
| Windowed/Divorced/Separated, N (%) | 23 (43) | 209 (30) | 140 (36) | 372 (33) | |
| Other,b N (%) | 7 (13) | 33 (5) | 21 (5) | 61 (5) | |
| Race | <0.001 | ||||
| White, N (%) | 50 (94) | 631 (91) | 320 (82) | 1,001 (88) | |
| African American, N (%) | 1 (2) | 49 (7) | 58 (15) | 108 (10) | |
| Other,c N (%) | 2 (4) | 17 (2) | 13 (3) | 32 (3) | |
| Living arrangement, % | 0.003 | ||||
| Living alone, N (%) | 23 (43) | 191 (27) | 117 (30) | 331 (29) | |
| Living with spouse, N (%) | 23 (43) | 455 (65) | 228 (58) | 706 (62) | |
| Living with others,d N (%) | 7 (13) | 51 (7) | 46 (12) | 104 (9) | |
| Residence | 0.134 | ||||
| Community, N (%) | 51 (96) | 691 (99) | 387 (99) | 1,129 (99) | |
| Facility,e N (%) | 2 (4) | 6 (1) | 4 (1) | 12 (1) | |
| Comorbidities | |||||
| Congestive heart failure, N (%) | 0 | 14 (2) | 13 (3) | 0.199 | 27 (2) |
| Diabetes, N (%) | 2 (4) | 63 (9) | 73*** (19) | <0.001 | 138 (12) |
| Stroke, N (%) | 3 (6) | 34 (5) | 29 (7) | 0.227 | 66 (6) |
| Hypertension, N (%) | 23 (43) | 341 (49) | 274*** (70) | <0.001 | 638 (56) |
| Hypercholesterolemia, N (%) | 16** (30) | 352 (51) | 237** (61) | <0.001 | 605 (53) |
| APOE genotype, N % | 0.673 | ||||
| No ϵ4 allele | 27 (51) | 365 (52) | 215 (55) | 607 (53) | |
| had ϵ4 allele | 26 (49) | 332 (48) | 176 (45) | 534 (47) | |
| BMI, mean (SD) | 18.9*** (1.0) | 24.1 (2.0) | 30.8*** (3.3) | <0.001 | 26.1 (4.3) |
| MMSE, mean (SD) | 26.9 (3.3) | 27.2 (2.4) | 27.2 (2.3) | 0.926 | 27.2 (2.4) |
| FAQ, mean (SD) | 3.5 (5.5) | 3.6 (5.0) | 3.9 (5.2) | 0.159 | 3.7 (5.1) |
| NPI-Q, mean (SD) | 1.7 (2.6) | 2.0 (3.0) | 2.6 (3.4) | 0.057 | 2.2 (3.1) |
| Global CDR, mean (SD) | 1.6 (0.5) | 1.7 (0.5) | 1.7 (0.5) | 0.136 | 1.7 (0.5) |
| CDR-SB, mean (SD) | 0.9 (1.0) | 1.2 (1.3) | 1.3 (1.3) | 0.229 | 1.2 (1.3) |
| GDS, mean (SD) | 2.1 (2.3) | 2.0 (2.1) | 2.1 (2.4) | 0.421 | 2.3 (2.3) |
| 1st degree family with dementia, N (%) | 32 (60) | 455 (65) | 255 (65) | 0.767 | 742 (65) |
| Year of follow-up since baseline, mean (SD) | 5.2 (2.6) | 5.2 (2.6) | 5.1 (2.6) | 0.971 | 5.2 (2.6) |
Note. MMSE, Mini-Mental State Exam; FAQ, Functional Activities; NPI-Q, Neuropsychiatric Inventory Questionnaire; CDR, clinical dementia rating; CDR-SB, clinical dementia rating sum of boxes; GDS, geriatric depression scale; SD, standard deviation.
Characteristics were compared using a nonparametric Kruskal-Wallis test for continuous covariates and χ2 test or the Fisher exact test (given the potential small number in certain cells) for categorical covariates. Pairwise comparisons (relative to moderate BMI; α level=0.05/2=0.025) would be conducted with adjusted p-value, if Kruskal-Wallis test or χ2 test (or the Fisher exact test) showed significant results.
Other included never married, living as married/ domestic partner, and unknown.
Other included American Indians, Alaskan Natives, Native Hawaiians, Asians, and individuals who identified themselves as multiracial.
Living with Others included living with relatives, or caregivers, and living with a group.
Facility included assisted living and nursing home.
Low BMI is <20 kg/m2, moderate BMI is 20 to <27.5 kg/m2, and high BMI is ≥27.5 kg/m2.
p < 0.005 and
p < 0.0005 indicated the results of pairwise comparisons.