DISTRIBUTION OF VITILIGO DURATION:

DISCUSSION

This study included 49 males and 48 females in <5 years duration, 6 males and 9 females in 6-10 years duration, 1 male and 3 females in 11-15 years duration, 2 males and 0 females in 16- 20 years duration, 1 male and 1 female in ≥21 years duration. Majority (80.83%) of the patients included in this study are affected by vitiligo for <5 years duration.

This is in accordance with other study done by Prakash D et al,159 where 75.55% cases had vitiligo for <5 years.

SERUM CHOLECALCIFEROL IN CASES vs CONTROLS:

There were 9 cases and 1 control with very severe deficiency, 22 cases and 4 controls with severe deficiency, 39 cases and 17 controls with deficiency, 28 cases and 12 controls with suboptimal levels, 21 cases and 26 controls with normal levels of serum cholecaciferol. One patient had above normal value of cholecalciferol.

All the patients with normal values and above normal value had been treated with phototherapy and the values were attributed to the same. They showed clinical improvement also. Thus, Serum cholecalciferol is low in cases (81.6%) compared to

controls (56.7%). Thus significant correlation exists between vitiligo and cholecalciferol. (P value<0.001 )

But, in the study done by Prakash D et al,159 there were no difference in serum cholecalciferol levels between cases and controls. In the Iranian study,160 cholecalciferol levels were lower in cases (Mean+S.D. 10.24+1.72) than controls (Mean+S.D. 18.31+7.39). In the study by Karagun E.,161 the patients’ serum vitamin D levels ranged from 6 to 42 ng/ml (mean: 12.04 ±8.84 ng/ml); in the control group they ranged from 8 to 39 ng/ml (mean: 12.91 ±6.08 ng/ml). The patients had lower circulating vitamin D levels than controls, but this difference was not significant (p = 0.570). In the study by Takci Z., 162 72.73% of the cases and 30.2% controls had deficiency. Thus, our study is in accordance with the study done by Tackci Z.

CORRELATION OF S. CHOLECALCIFEROL WITH TYPE OF VITILIGO:

In focal vitiligo, 2 patients had severe deficiency, 12 had deficiency and 1 had normal value. In mucosal vitiligo, 2 patients had severe deficiency, 10 had deficiency and 5 had normal values. In segmental vitiligo, 5 patients had severe deficiency, 6 had deficiency and 3 had normal values. In acrofacial vitiligo, none had severe deficiency, 10 had deficiency and 3 had normal values. In vitiligo vulgaris, 17 patients had severe deficiency, 27 had deficiency and 10 had normal values. In vitiligo universalis, 5 had severe deficiency, 2 had deficiency and none had normal values.

Though all the patients of all the vitiligo types with severe deficiency and deficiency outnumbers those having normal values of cholecalciferol, this study showed exclusively deficiency and severe deficiency with vitiligo vulgaris and

universalis which implies a significant correlation (P value- 0.025) with the type of vitiligo. Ten persons (18.5%) with normal values in vitiligo vulgaris were under phototherapy and are clinically improving.

But, in the study done by Prakash D et al,159 there is no change in cholecalciferol levels with the type of vitiligo.

CORRELATION OF S. CHOLECALCIFEROL WITH DURATION:

In < 5 years duration, 19(61.3%) patients had severe deficiency, 61(91%) had deficiency and 17(77.3%) had normal values. In 6-10 years duration, 8(25.8%) patients had severe deficiency, 6(9%) had deficiency and 1(4.5%) had normal value. In 11-15 years duration, 3(9.7%) patients had severe deficiency, none had deficiency and 1(4.5%) patient on phototherapy had normal value. In 16-20 years duration, 1(3.2%) had severe deficiency and 1(4.5%) patient on phototherapy had normal value. In >21 years duration, 2(9.1%) patients on phototherapy had normal values and none had deficiency or severe deficiency. This study shows significant correlation (P value- 0.001) with duration of vitiligo. Among patients with vitiligo for > 5 years duration, only 5 show normal values and all these patients were under phototherapy and showed clinical improvement. Majority of the patients were suffering from vitiligo for <5 years duration, majority (80) had deficiency and severe deficiency while only 17 had normal cholecalciferol values.

But, in the study done by Prakash D et al,159 there is no change in cholecalciferol levels with the duration of vitiligo.

CORRELATION OF S.CHOLECALCIFEROL WITH SEVERITY (VASI

Score):

In VASI <10% group, 10 patients had severe deficiency, 43 had deficiency and 17 had normal values. In VASI 11-25%, 8 patients had severe deficiency, 20 had deficiency and 3 had normal values. In VASI 26-50%, 8 had severe deficiency, 2 had deficiency and none had normal values. In VASI >75%, 5 patients had severe deficiency, 2 had deficiency and none had normal values.

This study shows significant correlation (P value<0.001) with the severity of vitiligo. In VASI score >26%, none of them show normal values, except 2 (9.1%) who were under phototherapy were clinically improving.

But, in the study by Takci Z., 162_{there was no change in cholecalciferol levels with}

the severity of vitiligo patients.

VARIATION OF S. CHOLECALCIFEROL WITH AGE AMONG CASES:

In age ≤20 years, 11 have severe deficiency, 15 have deficiency and none had normal values. In 21-40 years, 12 have severe deficiency, 22 have deficiency and 9 have normal values. In 41-60 years, 8 have severe deficiency, 25 have deficiency, and 10 have normal values. In ≥ 61 years, 5 have deficiency and 3 have normal values while none showed severe deficiency.

Thus, in the age group of <20years, none showed normal values. In age group of >60years, none of them showed severe deficiency. This indirectly shows the minimal

sun exposure among younger age groups and higher outdoor activities in older age group. Moreover, phototherapy is started in comparatively older age group.

In the study done by Prakash D et al,159 there is no change in cholecalciferol levels with the age of vitiligo patients. In the study by Karagun E.,161 there is no change in cholecalciferol levels with the age of vitiligo patients. In the study by Takci Z., 162

there is no change in cholecalciferol levels with the age of vitiligo patients.

VARIATION OF S. CHOLECALCIFEROL WITH AGE AMONG

CONTROLS:

In age ≤20 years, none had severe deficiency, 12 had deficiency, 1 had normal value. In 21-40 years, 4 had severe deficiency, 10 had deficiency and 9 had normal values. In 41-60 years, none had severe deficiency, 6 had deficiency and 15 had normal values. In ≥ 61 years, none had severe deficiency, 2 had deficiency and 1 had normal value.

Thus, in age group<40 years, those with severe deficiency and deficiency, outnumbers those with normal values while in age group>40 years, those with normal values are greater than those with deficiency. None of the studies compared age of the controls with cholecalciferol.

VARIATION OF S. CHOLECALCIFEROL WITH SEX AMONG CASES:

There are 11 males and 20 females with severe deficiency, 37 males and 30 females with deficiency and 11 males and 11 females with normal values.

In the study done by Prakash D et al,159 there is no change in cholecalciferol levels with the sex of vitiligo patients. In the Iranian study,160 _{Male patients had lower}

levels of vitamin D compared to controls (7.25 ng/ mL vs. 13.31ng/mL, P=0.03) while no significant difference was observed between female patients and controls (14.12 ng/mL vs. 16.25 ng/mL, P=0.51). In the study by Karagun E.,161 there is no change in cholecalciferol levels with the sex of vitiligo patients. In the study by Takci Z., 162 there is no change in cholecalciferol levels with the sex of vitiligo patients.

In this study, in both cases and controls, there is no sex prediliction (P value- 0.191) for serum cholecalciferol in normal and deficient groups which was consistent with other studies, though females show a greater preponderance to severe deficiency.

VARIATION OF S. CHOLECALCIFEROL WITH SEX AMONG

CONTROLS:

Among controls, there are 0 males and 4 females with severe deficiency, 16 males and 14 females with deficiency and 13 males and 13 females with normal values.

Thus, here also severe deficiency is more commonly seen with females. Otherwise, there was no significant correlation of cholecalciferol with sex . None of the other studies compared cholecalciferol variation in sex of control group.

CORRELATION OF S.CHOLECALCIFEROL WITH UV EXPOSURE IN

CASES:

Among those exposed to UV rays by phototherapy or natural sun exposure, there are 6 cases with severe deficiency, 15 cases with deficiency and 21 with normal values. In comparison, in those who are not exposed to UV rays, there are 25 with severe deficiency, 52 with deficiency and 1 with normal value thus suggesting significant correlation of serum cholecalciferol (P value<0.001) with UV exposure either due to phototherapy or due to natural sunlight exposure.

There is no case control study that assessed cholecalciferol levels with UV exposure. But, this study is in accordance with the study done by Sehrawat et al8_{and the study}

done by Danilo et al.15

CORRELATION OF S.CHOLECALCIFEROL WITH UV EXPOSURE IN

CONTROLS: Among the controls who are exposed to UV rays by natural sun exposure, there is none with severe deficiency, 2 with deficiency and 7 with normal values. In those who are not exposed to UV rays, there are 4 with severe deficiency, 28 with deficiency and 19 with normal values. But, the correlation of cholecalciferol is not significant (P value-0.073) with UV exposure. None of the other studies compared UV exposure of controls with cholecalciferol.

SUMMARY

 Of the total 180 people included in this study, 120 were vitiligo cases and 60 were age and sex matched controls.

 The study included 26 cases and 13 controls in the age <20 years, 43 cases and 23 controls in 21-40 years, 43 cases and 21 controls in 41-60 years, 8 cases and 3 controls in >60 years. Thus, the age of cases and controls are matched with a p value of 0.968.

 This study included 59 cases, 29 controls in male gender and 61 cases, 31 controls in female gender. Thus, the sex of cases and controls are matched with a p value of 0.916.

 This study shows higher preponderance of vitiligo vulgaris (45%).

 Focal, mucosal and universal vitiligo were commonly seen in females (41%) while segmental and acrofacial vitiligo were commonly seen in males (32.2%).

 Majority (80.83%) of the patients included in this study are affected by vitiligo for less than 5 years duration. Thus it implies the early health seeking behaviour due to the social stigma of the disease.

 Serum cholecalciferol is low in cases (81.6%) compared to controls (56.7%). Normal cholecalciferol values among the remaining vitiligo patients could be attributed to UV radiation either in the form of phototherapy and regular exposure of sun due to their occupation. The patients under phototherapy showed clinical improvement following phototherapy.

 Serum cholecalciferol deficiency is more commonly associated with vitiligo vulgaris (36.66%) and universal vitiligo (5.83%). Ten patients of vitiligo vulgaris having normal values are under phototherapy and show clinical improvement. Thus, there is significant correlation of serum cholecalciferol with the type of vitiligo (P value- 0.025).

 Serum cholecalciferol deficiency is noted in patients irrespective of the duration of vitiligo. But, in patients with disease duration of >5 years, all the 5 who had normal values are under phototherapy and show clinical improvement and others have either deficiency or severe deficiency. Thus there is significant correlation (P value-0.001) of serum cholecalciferol with the duration of vitiligo.

 In patients with VASI > 26%, almost all had deficiency, except 2 patients under phototherapy and they show clinical improvement. Thus, significant correlation exist between serum cholecalciferol level and vitiligo severity (P value<0.001).

 In both cases and controls, serum cholecalciferol show some improvement with age since severe deficiency is less common in >40 years of age suggesting significant correlation with age. (P value-0.041 for cases and 0.002 for controls)

 In both cases and controls, there is no sex prediliction (P value- 0.191 for cases and 0.131 for controls) for serum cholecalciferol in normal and deficient groups, though females show a greater preponderance to severe deficiency.

 In both cases and controls, normal serum cholecalciferol levels were seen more commonly in those exposed to UV rays compared to those who are not

exposed. Significant correlation is seen in cases with P value of <0.001 and the association is not significant in control group with P value-0.073. The fact that the patients under phototherapy showed clinical improvement following phototherapy supports the role of vitamin D in the pathogenesis of vitiligo.

In document A study on the correlation of serum cholecalciferol level and vitiligo in patients attending Government Rajaji Hospital, Madurai (Page 78-89)