Latent profile analysis of vitamin D and its association with depression severity of hospitalized patients with bipolar depression

Figures & data

Table 1. The socio-demographic and clinical characteristics of case group

	All Patients n = 149	Normal serum vitamin D group n = 56 (37.6%)	Hypovitaminosis D group n = 93 (62.4%)	P value
Gender
Female n(%)	86(57.7)	33(60.7)	53 (57.0)	0.817
Male n(%)	63(42.3)	23(39.3)	40 (43.0)
Age (in years)	29.2 ± 14.4	28.2 ± 13.7	29.8 ± 14.8	0.503
Body Mass Index (BMI)	22.9 ± 4.2	22.2 ± 3.6	23.3 ± 4.5	0.137
Smoking
No n(%)	128(85.9)	46 (82.1)	82 (88.2)	0.306
Yes n(%)	21(14.1)	10 (17.9)	11 (11.8)
Admission season
Spring/Summer n(%)	62 (41.6)	33 (58.9)	29 (31.2)	0.001
Autumn/Winter n(%)	87 (58.4)	23 (41.1)	64 (68.8)
Post-treatment vitamin D	74.4 ± 17.2	88.5 ± 16.5	65.8 ± 10.9	0.007
Disease course (years)	5.7 ± 6.2	4.5 ± 3.8	6.3 ± 7.2	0.087
Number of episodes	2.4 ± 1.8	2.4 ± 1.8	2.5 ± 1.8	0.727
Duration of this episode (days)	21.3 ± 11.1	20.5 ± 9.9	21.8 ± 11.9	0.488
Baseline SDS score	62.6 ± 5.5	59.5 ± 4.1	64.4 ± 5.5	<0.001
Post-treatment SDS score	43.6 ± 6.1	41.0 ± 6.1	44.9 ± 5.7	0.494

Table 2. Model fitting results for one – to five-class solutions in LCA models.

Model	AIC	BIC	aBIC	BLRT	Class size (%)
1 profile	2519.942	2531.958	2519.299	–
2 profiles	2447.748	2468.776	2446.623	<0.001	76.5/23.5
3 profiles	2428.087	2458.127	2426.480	<0.001	16.1/32.9/51.0
2 profiles	2408.507	2447.558	2406.417	<0.001	1.3/16.1/32.2/50.3
5 profiles	2400.266	2448.329	2397.694	<0.001	0.7/1.3/16.8/31.5/49.7

Note. AIC = Akaike’s information criteria, BIC = Bayesian’s information criteria, aBIC = sample-size adjusted Bayesian's information criteria, LMR = Lo-Mendel-Rubin, BLRT = Bootstrap-based Likelihood Ratio Test Metrics

Figure 1. Comparison of the baseline and post-treatment vitamin D mean from the three latent profiles.

Table 3. Descriptive statistics for vitamin D level subgroup disaggregated by latent profile class.

	Profile 1: low-level profile n = 49, 32.9%		Profile 2: medium-level profile n = 76, 51.0%		Profile 3: high-level profile n = 24, 16.1%		F	P
	M	SE	M	SE	M	SE
Baseline vitamin D	55.0	8.4	73.1	10.7	92.4	11.1	118.0	<0.001
Post-treatment vitamin D	57.9	6.8	75.9	8.0	103.0	12.5	228.6	<0.001
Mean change*	2.9	9.6	2.8	13.3	10.5	14.7	3.815	0.024

* Mean change was calculated by subtracting the baseline vitamin D from the post-treatment vitamin D.

Figure 2. Logistic regression analysis models showing the associations between SDS improvement and vitamin D latent profiles (medium-level profile as the reference). Crude model: Unadjusted model. Model 1: Adjusted for age, gender, BMI, smoking and admission season. Model 2: Additionally adjusted for disease course, number of episodes, duration of this episode, and psychiatric treatment.

Figure 3. Odds ratios for the socio-demographic and clinical variables predicting latent profile membership. Abbreviation: OR odds ratio; CI Confidence interval.