Acne vulgaris is frequently associated with increased sebum excretion. Human sebum consists of squalene, esters of glycerol, wax and cholesterol, as well as free cholesterol and fatty acids. 1 It has been reported that the serum lipid profile of acne patients differs significantly from that in healthy controls. Male and female acne patients have significantly low plasma high‐density lipoprotein cholesterol (HDL‐C) levels. Total cholesterol (TC), low‐density lipoprotein cholesterol (LDL‐C), testosterone and progesterone levels are elevated in acne patients. 2 , 3 It indicates that the relationship of acne vulgaris and serum lipid profile needs further exploration. This study was designed to evaluate the relationship between plasma lipid profile and acne.

Statistical analysis was performed using SPSS software (SPSS, Chicago, IL, USA). Results are expressed as mean ± standard deviation. Student's t ‐test was used to compare the significance of the mean differences among the groups. The differences were considered significant at P < 0.05. One‐way anova was also used for comparison between more than two mean groups. The χ 2 ‐test was used to compare the difference of constituent ratio of acne patients and controls with plasma lipid profile in the abnormal range.

According to the Hayashi et al . grading system, 4 lesion count was used to classify acne into four groups. Based on the number of inflammatory eruptions on half of the face, acne was scored as: 0–5, mild; 6–20, moderate; 21–50, severe; and more than 50, very severe. 4 The normal ranges for the plasma lipid profile were based on the Chinese Prevention and Treatment of Dyslipidemia in Adults (2007) guidelines. 5

The subjects maintained a general diet and were in a stable living condition at least 2 weeks before the study, and avoided participating in strenuous exercise or becoming fatigued within 24 h of blood sampling. Subjects were required to have fasted for 12 h before venous blood samples were taken. Blood samples were collected in ethylenediaminetetraacetic acid tubes, and immediately centrifuged at 1500 g for 20 min at 4°C. Plasma was separated within 1 h after blood sample collection and kept at 4°C. The blood samples were analyzed within 24 h. Plasma TC, TG, HDL‐C and LDL‐C levels were estimated by commercially available enzymatic colorimetric tests. LP(a) was detected by immunoturbidimetry. Plasma lipid concentrations were determined with a Hitachi 7600 Biochemistry Automatic Analyzer (Hitachi, Tokyo, Japan).

The controls were not taking any medication and had no personal or family history of severe acne. Healthy volunteers had no acne lesions, or acne scar; no psoriasis; no alopecia; no gallbladder disease, diabetes or neuroendocrine disorders; no history of hypertension, liver or kidney dysfunction, heart disease, or cancer; and they had had mild acne in adolescence (or many years ago) but were not under any treatment for acne, to avoid the effect of other endocrine disturbance. Some healthy people who might have had mild acne that had been healed for >2 years without taken any medication were also recruited in the control group. Pregnant and lactating women were excluded from both groups.

Ethical approval was obtained from the ethics committees of The First Affiliated Hospital of Guangxi University of Chinese Medicine and Ruikang Hospital of Guangxi University of Chinese Medicine. Clinical data were collected from these acne patients and healthy volunteers during 2012–2014. The assessment of acne severity was based on the Hayashi et al . grading system. 4 Patients had not taken isotretinoin, doxycycline or other drugs to treat acne at least 1 month before the study. Diagnosis and assessment of acne severity was performed by only one dermatologist.

The standardized normal range of plasma lipid profile see from table 3. The constituent ratio of male and female patients with TC, TG, LDL‐C and LP(a) levels above the normal range were significantly higher than in the healthy control group (Table 3 ). However, the constituent ratio of male and female patients with LDL‐C of less than 2.06 mmol/L was significantly higher than in the control group ( P < 0.05). The ratio of LDL‐C/HDL‐C in severe male patients was significantly higher than in the control group ( P = 0.03 < 0.05).

There were 181 acne patients and 130 age‐ and sex‐matched healthy controls (Table 1 ). Plasma TC, LDL‐C and LP(a) levels in male and female patients with severe acne were significantly higher than those in the healthy control group ( P < 0.05). Male patients with severe and moderate acne had TG levels significantly higher than in the healthy control group ( P < 0.05) (Table 2 ). Plasma LP(a) in male and female patients with mild, moderate and severe acne was significantly higher than in the healthy control group ( P < 0.05). The youngest acne patient with high plasma LP(a) (>300) was a 12‐year‐old girl.

Discussion

The plasma lipid profile of acne patients in the present study was similar to that reported by El‐Akawi et al., but there were some differences. Plasma lipid profiles were influenced by many factors, namely, different nutritional status, lifestyle and diet.6, 7 Statistically, the standard deviation showed that there was a wide variation (and individual differences) in lipid levels among patients. Therefore, acne patients had elevated levels of TC, TG LDL‐C, LP(a) and ratio of LDL‐C/HDL‐C, but some groups did not differ significantly from those in the normal control group. The constituent ratio of acne patients with TC, TG, LDL‐C and LP(a) levels above the normal range were significantly higher than in the healthy control group. The ratio of LDL‐C/HDL‐C in male patients with severe acne was significantly higher than the control group. The ratio of LDL to HDL cholesterol is highly predictive of the risk of major cardiovascular events.8, 9

Clinically, LDL‐C levels below normal are common in patients with advanced tumors, AIDS, liver disease and cachexia.10 In 53 male and female acne patients, plasma LDL‐C levels were lower than normal. The acne patients with hypolipidemia, hyperlipidemia or normal plasma lipid profile had a common characteristic: they complained of excess sebum secretion on the face. In our clinical experience, acne patients with hypolipidemia need a diet high in protein and some vitamins.

Plasma LP(a) levels in male and female patients with acne were significantly higher than those in the control group. In some patients with mild, moderate and severe acne, plasma LP(a) levels were below 100 mg/L, but their TG, TC and LDL‐C were higher than normal. Some acne patients had TG, TC and LDL‐C within the normal range, but their plasma LP(a) was higher than normal (300 mg/L); four patients had plasma LP(a) even higher than 700 mg/L. Statistical analysis showed that LP(a) levels had a large standard deviation, which suggested a large range of values for plasma LP(a) level in acne patients. High plasma levels of LP(a) are a independent risk factor for coronary heart disease, cerebrovascular disease.11 Women with polycystic ovary syndrome (PCOS) have higher LP(a) levels and risk of cardiovascular disease (CVD) than normal controls.10 Acne is a common symptom and side‐effect of PCOS. High plasma LP(a) level may be an important contributing factor to PCOS and acne vulgaris in young women. Women with PCOS have higher LP(a) levels and risk of CVD than normal controls.12 Higher LP(a) level is another CVD risk factor11, 12 in women with acne and PCOS.

The study revealed that plasma lipid profile in acne patients does not just increase, but that there are also many acne patients in whom lipid profile is higher or lower than normal. There is insufficient evidence to support the suggestion that acne patients with abnormal lipid profiles have a high risk of suffering from certain diseases in the near future. However, it provides a new basis for further exploring the pathogenesis as well as new treatments of acne vulgaris. High‐dose administration of niacin (≥2000 mg/day) was recommended in treatment of acne patients, so as to regulate plasma lipid levels and inhibit inflammation,13 but this requires further study.