Table 2.

Mean serum sodium concentration and prevalence of hyponatremia in each group

	Serum sodium concentrationa, mmol/L
	study population	female ECPFF	female ICPFF	male ECPFF	male ICPFF
At admission	138.9 ± 3.6	139 ± 3.4	138.7 ± 4.0	138.7 ± 3.6	139.7 ± 3.4
Presurgery day	138.5 ± 3.8	138.6 ± 4	138.3 ± 3.8	138.4 ± 3.3	138.9 ± 3.2
Postsurgery days	139.4 ± 3.8	139.4 ± 3.2	138.9 ± 4.6	140.1 ± 4.1	139.4 ± 3.3
At discharge	139.9 ± 4.6	140.5 ± 3.9	139.4 ± 4.1	139.5 ± 6.6	140.3 ± 3.3
Mean total	139 ± 3.9	139.2 ± 3.7	138.7 ± 4.1	139.1 ± 4.3	139.5 ± 3.4

	Prevalence of hyponatremia
	study population	female ECPFF	female ICPFF	male ECPFF	male ICPFF
At admission	9%	8%	11%	10%	5%
Presurgery day	13%	14%	17%	9%	8%
Postsurgery days	6%	6%	9%	0%	8%
At discharge	10%	8%	6%	19%	10%
Mean total	10%	9%	11%	9%	8%

ECPFF, extracapsular proximal femoral fracture; ICPFF, intracapsular proximal femoral fracture.

^aExpressed as mean ± SD.