TABLE 3.

Associations between tertiles of fatty acids and risk of osteoporotic fracture in a case-cohort study of participants in the AGES-Reykjavik Study¹

	Men					Women
				Model 1	Model 2				Model 1	Model 2
	IQR (%)	Cohort, n	Cases, n	HR (95% CI)	HR (95% CI)	IQR (%)	Cohort, n	Cases, n	HR (95% CI)	HR (95% CI)
SFA
Tertile 1	44.0–44.7	140	66	1.00	1.00	44.3–45.0	168	103	1.00	1.00
Tertile 2	45.2–45.5	153	53	0.71 (0.49, 1.02)	0.71 (0.49, 1.04)	45.4–45.7	150	122	1.12 (0.86, 1.46)	1.19 (0.91, 1.55)
Tertile 3	46.0–46.5	136	70	1.03 (0.73, 1.44)	1.10 (0.77, 1.56)	46.1–46.7	151	121	1.15 (0.89, 1.50)	1.22 (0.94, 1.59)
P-trend	—	—	—	0.85	0.56	—	—	—	0.29	0.15
MUFA
Tertile 1	13.1–14.2	160	46	1.00	1.00	13.4–14.4	164	107	1.00	1.00
Tertile 2	14.9–15.5	148	58	1.18 (0.80, 1.75)	1.15 (0.77, 1.72)	15.0–15.6	155	117	1.14 (0.88, 1.49)	1.17 (0.90, 1.52)
Tertile 3	16.3–17.6	121	85	1.62 (1.12, 2.34)	1.60 (1.09, 2.33)	16.3–17.6	150	122	1.10 (0.84, 1.43)	1.13 (0.86, 1.49)
P-trend	—	—	—	0.008	0.01	—	—	—	0.51	0.37
PUFA
Tertile 1	36.2–37.5	123	83	1.00	1.00	35.8–37.3	146	125	1.00	1.00
Tertile 2	38.3–38.8	145	61	0.79 (0.57, 1.11)	0.82 (0.58, 1.16)	38.0–38.6	147	125	1.09 (0.85, 1.40)	1.10 (0.85, 1.42)
Tertile 3	39.6–40.5	161	45	0.62 (0.43, 0.91)	0.60 (0.41, 0.89)	39.1–40.2	176	96	0.78 (0.59, 1.02)	0.76 (0.58, 1.00)
P-trend	—	—	—	0.01	0.01	—	—	—	0.08	0.06
n–6
Tertile 1	22.4–25.5	144	62	1.00	1.00	23.0–26.0	160	111	1.00	1.00
Tertile 2	27.5–28.8	133	73	1.32 (0.94, 1.86)	1.30 (0.92, 1.85)	27.8–29.2	132	140	1.34 (1.04, 1.72)	1.43 (1.10, 1.85)
Tertile 3	30.2–32.1	152	54	1.01 (0.70, 1.47)	0.97 (0.67, 1.42)	30.3–31.9	177	95	0.86 (0.65, 1.15)	0.91 (0.68, 1.21)
P-trend	—	—	—	0.92	0.91	—	—	—	0.36	0.56
n–3
Tertile 1	7.11–8.42	134	72	1.00	1.00	6.87–8.14	162	109	1.00	1.00
Tertile 2	9.78–11.2	141	65	0.89 (0.64, 1.25)	0.92 (0.65, 1.29)	9.12–10.3	146	126	1.16 (0.90, 1.51)	1.17 (0.90, 1.53)
Tertile 3	12.8–15.5	154	52	0.61 (0.43, 0.88)	0.66 (0.45, 0.95)	12.1–15.0	161	111	0.98 (0.75, 1.28)	0.93 (0.71, 1.23)
P-trend	—	—	—	0.009	0.03	—	—	—	0.87	0.60
n–6:n–3 ratio
Tertile 1	1.45–2.00	148	58	1.00	1.00	1.55–2.19	156	115	1.00	1.00
Tertile 2	2.44–2.93	143	63	1.27 (0.88, 1.82)	1.22 (0.85, 1.76)	2.73–3.20	146	126	1.10 (0.85, 1.42)	1.15 (0.89, 1.49)
Tertile 3	3.57–4.48	138	68	1.39 (0.97, 1.99)	1.32 (0.92, 1.90)	3.68–4.49	167	105	0.94 (0.71, 1.23)	0.99 (0.75, 1.30)
P-trend	—	—	—	0.07	0.14	—	—	—	0.66	0.95
LA
Tertile 1	13.6–15.7	140	66	1.00	1.00	13.7–15.9	155	116	1.00	1.00
Tertile 2	16.8–18.1	145	61	0.83 (0.59, 1.19)	0.83 (0.58, 1.19)	17.3–18.3	155	117	1.08 (0.83, 1.40)	1.10 (0.85, 1.43)
Tertile 3	19.5–21.5	144	62	0.97 (0.68, 1.38)	0.91 (0.63, 1.31)	19.5–21.0	159	113	0.99 (0.76, 1.29)	1.02 (0.78, 1.33)
P-trend	—	—	—	0.83	0.58	—	—	—	0.96	0.90
AA
Tertile 1	5.03–5.84	142	64	1.00	1.00	5.03–5.72	163	108	1.00	1.00
Tertile 2	6.37–7.12	143	63	1.25 (0.87, 1.78)	1.25 (0.87, 1.80)	6.39–7.02	145	127	1.41 (1.09, 1.83)	1.42 (1.09, 1.85)
Tertile 3	7.76–9.24	144	62	1.26 (0.87, 1.81)	1.26 (0.87, 1.84)	7.76–9.19	161	111	1.17 (0.89, 1.54)	1.24 (0.94, 1.64)
P-trend	—	—	—	0.22	0.22	—	—	—	0.25	0.12
ALA
Tertile 1	0.14–0.17	145	61	1.00	1.00	0.14–0.17	157	114	1.00	1.00
Tertile 2	0.19–0.22	146	60	0.89 (0.63, 1.28)	0.86 (0.60, 1.24)	0.20–0.22	148	124	1.15 (0.89, 1.49)	1.16 (0.90, 1.51)
Tertile 3	0.26–0.34	138	68	1.04 (0.73, 1.48)	0.99 (0.70, 1.42)	0.26–0.33	164	108	0.93 (0.71, 1.21)	0.91 (0.70, 1.19)
P-trend	—	—	—	0.81	1.00	—	—	—	0.59	0.50
EPA
Tertile 1	1.27–1.71	128	78	1.00	1.00	1.20–1.63	160	111	1.00	1.00
Tertile 2	2.23–2.96	144	62	0.81 (0.58, 1.14)	0.81 (0.57, 1.14)	2.04–2.52	145	127	1.19 (0.92, 1.55)	1.24 (0.95, 1.60)
Tertile 3	3.97–5.46	157	49	0.55 (0.39, 0.80)	0.59 (0.41, 0.86)	3.40–5.24	164	108	0.97 (0.74, 1.27)	0.96 (0.73, 1.26)
P-trend	—	—	—	0.001	0.005	—	—	—	0.82	0.77
DHA
Tertile 1	4.48–5.24	136	70	1.00	1.00	4.32–5.10	164	107	1.00	1.00
Tertile 2	6.02–6.83	146	60	0.75 (0.53, 1.06)	0.78 (0.54, 1.11)	5.74–6.33	146	126	1.28 (0.99, 1.66)	1.28 (0.98, 1.66)
Tertile 3	7.50–8.60	147	59	0.75 (0.53, 1.06)	0.80 (0.56, 1.14)	7.12–8.48	159	113	1.04 (0.79, 1.36)	1.28 (0.98, 1.66)
P-trend	—	—	—	0.10	0.21	—	—	—	0.80	0.92
DPA
Tertile 1	0.94–1.05	140	66	1.00	1.00	0.87–0.99	158	113	1.00	1.00
Tertile 2	1.14–1.22	148	58	0.74 (0.52, 1.06)	0.75 (0.52, 1.08)	1.07–1.15	151	121	1.03 (0.79, 1.33)	1.01 (0.78, 1.31)
Tertile 3	1.30–1.49	140	66	0.83 (0.59, 1.18)	0.87 (0.61, 1.24)	1.24–1.39	160	112	0.97 (0.74, 1.26)	0.91 (0.70, 1.20)
P-trend	—	—	—	0.33	0.48	—	—	—	0.82	0.51

¹Associations were tested by using multivariate Cox hazard models. Model 1 was adjusted for age at the AGES-Reykjavik Study baseline and education. Model 2 was adjusted as for model 1 and for smoking status, height, weight, prevalent diabetes, physical activity, and estrogen and glucocorticoid use. Tests for trend were performed by assigning the median value to each tertile and modeling this as a continuous variable. AA, arachidonic acid; AGES-Reykjavik, Age, Gene/Environment Susceptibility Study; ALA, α-linolenic acid; DPA, docosapentaenoic acid; LA, linoleic acid.