Table 3.

Multivariate adjusted odds ratios and 95% confidence intervals for frailty compared to no frailty by quintile of protein and amino acid intakes among 2108 elderly Japanese women

	Q1 (Lowest) (n = 421)	Q2 (n = 422)	Q3 (n = 422)	Q4 (n = 422)	Q5 (Highest) (n = 421)	P for trend
Protein*
Total protein, g/d	≤62.9	63.0-69.8	69.8-76.1	76.1-84.3	≥84.3
n of frailty/no frailty†	113/308	117/305	90/332	82/340	79/342
Age adjusted OR (95% CI)	1.00 (reference)	1.07 (0.78, 1.48)	0.76 (0.54, 1.05)	0.70 (0.50, 0.98)	0.65 (0.46, 0.91)	0.0008
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.02 (0.72, 1.45)	0.64 (0.45, 0.93)	0.62 (0.43, 0.90)	0.66 (0.46, 0.96)	0.001
Animal protein§, g/d	≤31.8	31.8-38.8	38.8-45.6	45.6-54.8	≥54.8
n of frailty/no frailty†	104/317	117/305	94/328	89/333	77/333
Age adjusted OR (95% CI)	1.00 (reference)	1.20 (0.87, 1.66)	0.88 (0.63, 1.22)	0.86 (0.61, 1.20)	0.71 (0.50, 1.00)	0.008
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.12 (0.79, 1.59)	0.76 (0.52, 1.09)	0.71 (0.49, 1.02)	0.73 (0.50, 1.06)	0.009
Plant protein||, g/d	≤27.1	27.1-29.4	29.4-31.2	31.2-33.9	≥33.9
n of frailty/no frailty†	117/304	102/320	82/340	98/324	82/339
Age adjusted OR (95% CI)	1.00 (reference)	0.82 (0.59, 1.13)	0.60 (0.43, 0.84)	0.71 (0.51, 0.98)	0.62 (0.44, 0.87)	0.003
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	0.73 (0.52, 1.04)	0.59 (0.41, 0.86)	0.72 (0.51, 1.04)	0.66 (0.45, 0.95)	0.04
Amino acids*
Essential amino acids, g/d	≤24.1	24.1-27.0	27.0-29.7	29.8-33.3	≥33.3
n of frailty/no frailty†	108/313	121/301	95/327	80/342	77/344
Age adjusted OR (95% CI)	1.00 (reference)	1.17 (0.85, 1.61)	0.86 (0.62, 1.20)	0.74 (0.52, 1.04)	0.67 (0.47, 0.94)	0.001
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.12 (0.79, 1.59)	0.72 (0.50, 1.05)	0.64 (0.44, 0.93)	0.69 (0.47, 1.00)	0.002
Branched chain amino acids, g/d	≤10.6	10.6-11.8	11.8-12.9	12.9-14.3	≥14.3
n of frailty/no frailty†	108/313	117/305	96/326	81/341	79/342
Age adjusted OR (95% CI)	1.00 (reference)	1.12 (0.81, 1.54)	0.85 (0.61, 1.18)	0.74 (0.53, 1.04)	0.68 (0.48, 0.96)	0.003
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.06 (0.75, 1.50)	0.75 (0.53, 1.08)	0.63 (0.43, 0.92)	0.70 (0.49, 1.02)	0.004
Leucine, g/d	≤4.78	4.78-5.31	5.31-5.82	5.82-6.44	≥6.45
n of frailty/no frailty†	110/311	116/306	94/328	82/340	79/342
Age adjusted OR (95% CI)	1.00 (reference)	1.08 (0.78, 1.48)	0.81 (0.58, 1.23)	0.74 (0.53, 1.04)	0.67 (0.47, 0.94)	0.002
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.02 (0.72, 1.45)	0.72 (0.50, 1.04)	0.63 (0.43, 0.92)	0.69 (0.48, 1.00)	0.004
Isoleucine, g/d	≤2.66	2.66-2.97	2.97-3.27	3.27-3.64	≥3.64
n of frailty/no frailty†	109/312	115/307	95/327	86/336	76/345
Age adjusted OR (95% CI)	1.00 (reference)	1.09 (0.79, 1.50)	0.83 (0.60, 1.16)	0.80 (0.57, 1.12)	0.64 (0.46, 0.91)	0.002
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.07 (0.75, 1.51)	0.74 (0.51, 1.06)	0.69 (0.47, 1.00)	0.68 (0.47, 0.98)	0.004
Valine, g/d	≤3.18	3.18-3.50	3.50-3.83	3.83-4.26	≥4.26
n of frailty/no frailty†	105/316	121/301	93/329	82/340	80/341
Age adjusted OR (95% CI)	1.00 (reference)	1.18 (0.86, 1.63)	0.86 (0.62, 1.20)	0.76 (0.54, 1.08)	0.72 (0.51, 1.01)	0.004
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.15 (0.81, 1.63)	0.76 (0.53, 1.10)	0.67 (0.46, 0.97)	0.74 (0.51, 1.08)	0.006
Sulfur amino acids, g/d	≤2.41	2.41-2.67	2.67-2.90	2.90-3.23	≥3.24
n of frailty/no frailty†	102/319	115/307	102/320	81/341	81/340
Age adjusted OR (95% CI)	1.00 (reference)	1.14 (0.82, 1.58)	0.99 (0.71, 1.38)	0.77 (0.55, 1.08)	0.74 (0.53, 1.05)	0.01
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.09 (0.77, 1.55)	0.86 (0.60, 1.23)	0.65 (0.45, 0.95)	0.73 (0.50, 1.06)	0.006
Methionine, g/d	≤1.45	1.45-1.64	1.64-1.81	1.81-2.04	≥2.04
n of frailty/no frailty†	100/321	119/303	100/322	84/338	78/343
Age adjusted OR (95% CI)	1.00 (reference)	1.23 (0.89, 1.70)	1.02 (0.73, 1.41)	0.80 (0.57, 1.13)	0.74 (0.52, 1.04)	0.008
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.14 (0.80, 1.62)	0.89 (0.62, 1.28)	0.67 (0.46, 0.97)	0.74 (0.51, 1.08)	0.006
Cysteine, g/d	≤0.97	0.97-1.04	1.04-1.11	1.11-1.20	≥1.20
n of frailty/no frailty†	104/317	120/302	90/332	95/327	72/349
Age adjusted OR (95% CI)	1.00 (reference)	1.24 (0.90, 1.71)	0.85 (0.61, 1.19)	0.92 (0.66, 1.28)	0.65 (0.46, 0.92)	0.003
Multivariate adjusted OR (95% CI)‡	1.00 (reference)	1.26 (0.89, 1.78)	0.73 (0.50, 1.06)	0.85 (0.59, 1.23)	0.67 (0.46, 0.98)	0.005

CI, confidence interval; OR, odds ratio.

*Protein and amino acid intakes were energy-adjusted according to the residual method.

†Frailty score (0-5) was defined as the sum of poor physical function (two points), exhaustion (one point), low physical activity (one point), and unintentional weight loss (one point). A score ≥3 were classified as frailty.

‡Adjusted for age (y, continuous), body mass index (kg/m², continuous), residential block (Hokkaido and Tohoku, Kanto, Hokuriku and Tokai, Kinki, Chugoku and Shikoku, and Kyushu), size of residential area (city with a population ≥1 million, city with a population <1 million, and town and village), living alone (yes or no), current smoking (yes or no), alcohol drinking (yes or no), dietary supplement use (yes or no), history of chronic disease (any of stroke, myocardial infarction, hypertension, diabetes, or chronic rheumatism; yes or no), depression symptoms (yes or no), and energy intake (kcal/d, continuous).

§Protein from the following four food groups were included in animal protein: fish and shellfish, meat, eggs, and dairy products.

||Protein from the following eight food groups were included in plant protein: cereals, pulses, potatoes, confectionaries, fruits, vegetables, alcoholic beverages, and non-alcoholic beverages.