Relationship of Whole Blood Zinc Levels to Acne Severity

Acne Vulgaris is a disorder of the pilosebaceous unit characterized by formation of comedones, papules, pustules, inflamed nodules, and cysts.1 Most common predilection sites are those with hormonally sensitive sebaceous glands such as the face, neck, chest, upper back and upper arms. Acne can persist for years and result in disfigurement and permanent scarring. It can cause serious adverse effects on psychosocial development, resulting in emotional problems, withdrawal from society, and depression. Nearly all adolescents experience different severity levels of acne vulgaris, with moderate to severe levels affecting around 20% of this population. In the Philippines, high school students were found to have a mild impairment of quality of life (QOL) due to acne, regardless of severity. Despite the known treatment regimens for acne, people are still suffering from the effects of the disease.

Acne has four main pathogenic contributors: follicular hyperkeratinization, increased sebum production, Propionibacterium acnes (P. acnes) within the follicle, and inflammation. Reports show that antibiotic resistance is a growing issue in the treatment regimen of acne vulgaris, making it less and less suitable for long-term treatment. Other options that can be substitutes or adjuncts to treatment may be useful in this condition.

Zinc is an essential element for normal epithelial differentiation and for normal development. It has also been shown to have antioxidant properties. At present, there is paucity of data regarding the role of zinc levels in the development or severity of acne vulgaris. Also, data on favorable effects of dietary factors such as zinc, omega-3 fatty acids, antioxidants, vitamin A, and dietary fiber on acne vulgaris are limited specially in the Philippines.

This study will be conducted to measure the whole blood zinc levels in patients with acne vulgaris and compare it with healthy controls. This aims to determine the relationship between whole blood zinc levels and disease severity in Filipino patients with acne vulgaris in order to bring new insight to guide further studies regarding zinc's role in the pathogenesis and possible further treatment of acne vulgaris in the Philippines.

Significance of the Study:

While a number of studies have been conducted comparing serum zinc levels with acne vulgaris, no previous studies have been done in the Philippine setting that assesses the relationship of whole blood zinc levels with the severity of acne. Given that acne vulgaris is one of the most common dermatologic diagnoses in the Philippine population, and the increasing resistance to antibiotics commonly used to treat acne, studies about other treatment modalities for acne vulgaris that do not have resistance factors are timely and significant in the country.

For long-term or maintenance therapy, physicians should consider effectivity, cost, and adverse effects. By determining the relationship of whole blood zinc levels to acne severity among Filipinos 18-25 years old, this study can be used as evidence for giving zinc supplements to Filipino people diagnosed with acne vulgaris if a significant relationship is found. Since zinc is more cost-effective and has less adverse effects compared to most antibiotics, this may prove helpful for the Filipino patient in terms of safety and economy for long-term therapy. Furthermore, this study may also be able to provide more information for further studies towards non-antimicrobial treatment regimens for acne vulgaris in the Philippines.

Research Question:

Is there a relationship between whole blood zinc levels and the severity of acne vulgaris in Filipino patients 18-25 years old versus normal controls?

Null Hypothesis: There is no relationship between whole blood zinc levels and the severity of acne vulgaris.

Alternative Hypothesis: There is a relationship between whole blood zinc levels and the severity of acne vulgaris.

Objectives:

• To study the relationship between whole blood zinc levels and the severity of acne vulgaris in Filipino patients 18-25 years old and normal controls
• To describe the clinical profile of Filipino patients 18-25 years old with acne vulgaris
• To determine the whole blood zinc levels of acne patients compared to controls
• To determine the relationship of the clinical severity of acne vulgaris to whole blood zinc levels

A cross-sectional comparative study design will be utilized for this study which will be conducted from November 2017 to March 2018. The study will be conducted at the Dermatology Out-patient Clinic of the East Avenue Medical Center (EAMC).

STUDY PROCEDURE

1. The study will be submitted to the Technical Review Board and Institution Ethics and Review Board for approval.
2. In the Dermatology Out-Patient Department of East Avenue Medical Center, patients seeking consult for their skin lesions which were diagnosed to be Acne Vulgaris will be screened if they meet the inclusion/exclusion criteria.
3. Informed consent will be obtained for those who are qualified.
4. Patients will be given proper treatment whether they agree to participate or not. For the patients who agree to participate, the investigator will assess the patient's acne severity using the Global Acne Grading Scale (GAGS).
5. Twelve milliliters of blood will be extracted from the patient with proper aseptic technique and waste disposal.
6. Blood sample will be properly stored in three EDTA tubes, labelled, and transported to the laboratory for determination of whole blood zinc levels through ashing acid digestion- inductively coupled plasma (ICP) using Shimadzu ICPS-7510, an inductively coupled plasma emission spectrometer.
7. Blood samples are viable and stable for 5 days at 15-25 degrees Celsius.
8. A memorandum of agreement between the principal investigator and Hi-Precision Diagnostics, Inc. has been made. Hi-Precision Diagnostics will be providing the materials for extraction, picking-up, and transporting the blood sample using a special insulated medical specimen bag (Versapak Pathology and Specimen bag) with ice packs and thermometer to help maintain the ideal temperature of 15-25 degrees Celsius.
9. Schedule of specimen pick-up is from 8:00 am- 8:00 pm and may be done on an as-needed basis. The blood specimens will be stored in the refrigerator immediately after extraction.
10. Results will be obtained by the investigator via the online results portal of the laboratory.
11. Data collected will be tabulated and data analysis will be done.

PASS 2008 was used for the computation of minimum sample size. Parameters for the computation was obtained from previously published studies. For the one-way ANOVA, a minimum of 40 patients (10 for each acne severity: mild, moderate and severe acne and 10 for controls) achieves 95% power to detect differences among the means versus the alternative of equal means using an F test with a significance level of 0.05. The size of the variation in the means is represented by their standard deviation which is 13.30 mg/dL and the common standard deviation within a group is assumed to be 20.00 mg/dL.

Data will be encoded by the researcher in MS Excel. The excel file will be converted into Stata file for further data processing and analysis. Stata SE version 12 will be used for both descriptive and inferential statistics. Quantitative variables will be presented as mean or median while qualitative variables will be presented as percentages.

In order to compare the whole blood zinc levels between cases and controls, independent T-test will be used. ANOVA will be used to compare the whole blood zinc levels by acne severity. Multiple linear regression analysis will then be performed in order to determine the association of whole blood zinc levels with acne severity after controlling for the effects of significant confounding variables. All p values ≤ 0.05 will be considered as significant.

The correlation of whole blood zinc levels with severity of acne vulgaris in Filipino patients may help clinicians recommend more detailed dietary advice and add non-antibiotic supplements to their current treatment of acne vulgaris. The results of the study can serve as a guide for further studies related to whole blood zinc and its role in the pathogenesis of acne vulgaris in Filipino patients.