. 2021 Apr 6;129(4):047005. doi: 10.1289/EHP7404

Table 2.

Cross-sectional mean differences in BMD [ $β$ coefficients (95% CI), ${g / cm}^{2}$ ] across tertiles of urinary fluoride (mg/g creatinine) ( $n = 4,306$ ) and dietary fluoride (mg/d) ( $n = 4,072$ ) with BMD at the lumbar spine and femoral neck.

Categories	Tertiles of urinary fluoride			$p_{Trend}$	Tertiles of dietary fluoride			$p_{Trend}$
Categories	1	2	3	$p_{Trend}$	1	2	3	$p_{Trend}$
$N$	1,436	1,435	1,435		1,358	1,357	1,357
Fluoride exposure {mg/g creatinine or mg/d [median (range)]}	0.68 (0.14–0.88)	1.08 (0.88–1.30)	1.64 (1.30–116.51)		1.38 (0.26–1.74)	2.04 (1.74–2.41)	2.94 (2.41–11.16)
Lumbar spine
Age-adjusted $β$ (95% CI)	Ref	$- 0.013$ ( $- 0.028$ , 0.001)	$- 0.023$ ( $- 0.037$ , $- 0.009$ )		Ref	0.003 ( $- 0.011$ , 0.018)	0.019 (0.004, 0.033)
Multivariable-adjusted $β$ (95% CI)^a	Ref	0.007 ( $- 0.006$ , 0.020)	0.013 (0.000, 0.027)	0.05	Ref	0.005 ( $- 0.008$ , 0.019)	0.017 (0.004, 0.031)	0.01
Femoral neck
Age-adjusted $β$ (95% CI)	Ref	$- 0.003$ ( $- 0.011$ , 0.005)	$- 0.012$ ( $- 0.020$ , $- 0.003$ )		Ref	0.006 ( $- 0.003$ , 0.014)	0.010 (0.001, 0.018)
Multivariable-adjusted $β$ (95% CI)^a	Ref	0.007 ( $- 0.001$ , 0.015)	0.009 (0.001, 0.016)	0.04	Ref	0.007 ( $- 0.001$ , 0.015)	0.008 (0.000, 0.017)	0.05

Note: The total number of participants in the urinary fluoride and dietary fluoride analyses were 4,306 and 4,072, respectively. Two hundred thirty-four women were excluded from the dietary fluoride analyses because of missing dietary fluoride information due either to responding to a shorter version of the FFQ or having missing/inadequate reported dietary intake (energy intake outside 3 SD of the log-transformed mean). BMD, bone mineral density ( ${g / cm}^{2}$ ); CI, confidence interval; eGFR, estimated glomerular filtration rate; FFQ, food frequency questionnaire; Ref, reference; SD, standard deviation.

^{^a}

Multivariable-adjusted models were adjusted for age, education, height, total fat mass, lean body mass, parity, smoking status, physical activity, alcohol intake, diabetes, eGFR, tertiles of urinary excretion of calcium (for urinary fluoride) or tertiles of dietary intake of calcium (for dietary fluoride), use of calcium supplements, use of vitamin D supplements, ever use of estrogen, and ever use of corticosteroids. Urinary fluoride models were additionally adjusted for serum Beta-CrossLaps (ng/L).