. 2022 Sep 16;116(6):1565–1579. doi: 10.1093/ajcn/nqac255

TABLE 6.

Changes in renal function parameters according to quartiles of 1-y changes in betaine intake¹

Variables	Total n	Q1 (−87.8 to −18.2 mg/d) (n = 812)	Q2 (−18.1 to −2.1 mg/d) (n = 855)	Q3 (−2.0 to 16.3 mg/d) (n = 823)	Q4 (16.4–99.0 mg/d) (n = 877)	P model 1	P model 2	P model 3	P-linear trend
Δ Urea, mg/dL	3046	0.91 ± 10.76	0.50 ± 8.99	1.16 ± 10.99	0.85 ± 8.66	0.754	0.754	0.742	0.360
Δ Creatinine, mg/dL	3349	0.01 ± 0.35	0.00 ± 0.12	0.00 ± 0.12	0.00 ± 0.11	0.568	0.568	0.534	0.293
Δ Uric acid, mg/dL	3260	0.02 ± 1.96	0.33 ± 6.12	−0.08 ± 1.40	−0.01 ± 2.45	0.364	0.365	0.361	0.805
Δ Urine creatinine, mg/dL	3332	−2.49 ± 53.83	0.19 ± 57.39	−4.16 ± 52.67	−5.74 ± 56.70	0.091	0.091	0.042	0.004
Δ eGFR, mL · min⁻¹ · 1.73m⁻²	3349	0.12 ± 9.39	0.06 ± 9.29	−0.20 ± 8.83	−0.17 ± 8.48	0.417	0.417	0.478	0.617
eGFR, >10% decrease, yes	3349	90 (10.4)	118 (13.3)	120 (14.4)	133 (14.7)	0.180	0.180	0.179	0.285
Δ UACR, mg/g	3367	2.83 ± 44.90	2.47 ± 42.02	0.37 ± 36.70	0.61 ± 36.85	0.158	0.158	0.148	0.300

Total n = 3367. Values are mean ± SD or n (%) unless otherwise indicated. Betaine intake was adjusted by energy residuals. Characteristics among quartiles were compared using 1-factor ANOVA. Model 1: adjusted by sex, age, and center. Model 2: adjusted by sex, age, center, civil status, education, smoking habits, sedentary lifestyle, and choline intake at baseline. Model 3: adjusted by sex, age, center, civil status, education, smoking habits, sedentary lifestyle, choline intake at baseline, adherence to an er-MedDiet and changes in adherence to an er-MedDiet, energy intake and changes in energy intake, and PA and changes in PA. P-linear trend: adjusted by age, sex, center, BMI, and energy intake at baseline. eGFR, estimated glomerular filtration rate; er-MedDiet, energy-restricted traditional Mediterranean diet; PA, physical activity; Q, quartile; UACR, urine albumin:creatinine ratio.