Is there a non-linear relationship between dietary protein intake and prostate-specific antigen: proof from the national health and nutrition examination survey (2003–2010)

Table 2 Univariate and multivariate analysis by weighted linear regression model and GAM model

Exposure	Non-adjusted model	Minimally-adjusted model	Fully-adjusted model	GAM model
PSA (ng/ml) log2 transform
Dietary Protein (gm)	-0.028 (-0.036, -0.021) <0.00001	-0.002 (-0.010, 0.005) 0.52921	0.015 (-0.024, 0.055) 0.44749	0.023 (-0.018, 0.064) 0.28372
Dietary Protein (quartile)
Q1	0	0	0
Q2	0.002 (-0.101, 0.105) 0.96758	0.098 (-0.003, 0.200) 0.05821	0.238 (-0.392, 0.868) 0.46152	0.383 (-0.244, 1.009) 0.23490
Q3	-0.194 (-0.293, -0.094) 0.00015	0.006 (-0.095, 0.106) 0.91227	-0.552 (-1.105, 0.001) 0.05422	-0.315 (-0.914, 0.284) 0.30596
Q4	-0.352 (-0.449, -0.255) <0.00001	-0.036 (-0.137, 0.064) 0.47562	-0.078 (-0.577, 0.422) 0.76110	0.114 (-0.434, 0.662) 0.68479
P for trend	<0.00001	0.11763	0.47163	0.94157

Noted:Non-adjusted model adjust for: None
Minimally-adjusted model adjust for: Race/Ethnicity; Poverty income ratio; Age,year; marital status, education level
Fully-adjusted model adjust for: Vitamin D intake (mcg); LDL-cholesterol (mg/dL); Race/Ethnicity; Poverty income ratio; Body mass index,Kg/m2; Alcohol (gm) first day; C-reactive protein (mg/dL); Glycohemoglobin (%); HDL; Hypertension history; Diabetes history; coronary heart disease; stroke; cigarettes per day during past month; Age,year; Marital Status; Average level of physical activity each day; Enlarged prostate; Triglycerides (mg/dL), education level
GAM model:Adjust II model adjust for: Vitamin D intake (mcg) (Smooth); LDL-cholesterol (mg/dL) (Smooth); Race/Ethnicity; Poverty income ratio; Body mass index,Kg/m2(Smooth); Alcohol (gm) first day(Smooth); C-reactive protein (mg/dL) (Smooth); Glycohemoglobin (%)(Smooth); HDL(Smooth); Hypertension history; Diabetes history; coronary heart disease; stroke; cigarettes per day during past month(Smooth); Age,year(Smooth); Marital Status; Average level of physical activity each day; Enlarged prostate; Triglycerides (mg/dL)(Smooth), education level

ISSN: 1476-511X