Table 4. Associations between homozygous CC genotype of +1127 INS-PstI and characteristics of prostate cancer at diagnosis.

Dependent variable	Number of cases	Percent with homozygous CC	Univariate P-value	Adjusted OR (95% CI)	Multivariable P-value
Gleason score
2–6	116	84	0.034	2.60 (1.15–5.88)a	0.022
⩾7	52	69
Age at diagnosis
<55	26	69
55–64	72	79
⩾65	80	84	0.121b	2.10 (1.01–4.33)c	0.046

^aOdds ratios for the risk of having a low Gleason score <7 were obtained from logistic regression analysis, when the subjects with homozygous CC were compared with those with other genotypes (reference category). Odds ratio was adjusted for age at diagnosis (<55, 55–64, or ⩾65) and frequency of seeing a doctor for physical examination (less than once a year, once a year, or more than once a year).

^bP for trend.

^cOdds ratios were estimated from ordinal logistic regression analysis. The positive odds ratio (2.10) indicates that the subjects with homozygous CC were more likely to be in a higher category of age at diagnosis (i.e. diagnosed at a later age) than subjects with other genotypes. The odds ratio was adjusted for Gleason score (2–6 or ⩾7) and frequency of seeing a doctor for physical examination.