Between December 2012 and June 2014, 164 patients attended our facility and of these, 100 agreed to participate in the study. The male: female ratio was 31:69. There was one patient of Black African descent, five of Irish Traveler descent and 94 of White European descent. The mean age was 53.7 ± 11.3 (range 31.1–80) years. The mean number of skin tags was 10.5 ± 18.4 (range 0-135). Tags were present in 85 patients and absent in 15. Skin tags were present only in the axillae in 30 patients, only on the neck in 11 patients and 44 patients had skin tags in both the axillae and the neck. 62 patients had three or more skin tags while 38 had two or fewer. 12 patients were current smokers while 88 were previous or never smokers. 14 patients reported a current or past history of sleep apnea while 4 had previous bariatric surgery. 41 patients were currently taking antihypertensive therapy (59 were not), 37 were taking medication for type 2 diabetes (none had type 1 diabetes) and 36 patients were taking lipid lowering therapy (either statin or fibrate). Of the 37 patients with diabetes, 35 had skin tags (94.6%), compared to 50 of 63 patients without diabetes (79.4%, p = 0.039). Put another way, 59% of those with skin tags, compared to 13% of those with no tags had diabetes. Skin tags were present in 79.7% of female and 96.8% of male patients (p = 0.027). 45.8% of patients with skin tags compared to 13.3% with no tags were on antihypertensive therapy (p = 0.018), while 38.8% and 20%, respectively, were on lipid lowering therapy (p = 0.16).
The anthropometric and metabolic characteristics of study participants with any skin tags compared to those with no skin tags are presented in Table 1. Those with any skin tags had higher SBP and fasting blood glucose and a higher HbA1c. There was a (statistically non-significant) trend to higher triglyceride:HDL cholesterol ratio in those with skin tags, consistent with them being more insulin resistant. Likewise, there were non-significant trends to increased weight and diastolic blood pressure in those with versus those without any skin tags.
Table 1
Anthropometric and metabolic characteristics of adults with severe obesity comparing those with either axillary or cervical skin tags to those with no skin tags.
Variable | No Skin tags | Any Skin tags | P-value |
| n | 15 | n | 85 | |
Systolic blood pressure (mmHg) | 125.1 | ± 8.3 | 138.0 | ± 16.0 | < 0.001 |
Diastolic blood pressure (mmHg) | 80.4 | ± 9.7 | 85.6 | ± 9.7 | 0.094 |
Total Cholesterol (mmol/L) | 5 | ± 1.0 | 4.6 | ± 1.2 | 0.19 |
LDL Cholesterol (mmol/L) | 3.1 | ± 0.9 | 2.6 | ± 1.2 | 0.136 |
HDL Cholesterol (mmol/L) | 1.3 | ± 0.3 | 1.2 | ± 0.3 | 0.329 |
Triglycerides (mmol/L) | 1.5 | ± 0.7 | 1.8 | ± 1.1 | 0.351 |
Triglyceride:HDL | 1.3 | ± 0.6 | 1.7 | ± 1.4 | 0.054 |
Total Cholesterol (mmol/L)+ | 5.3 | ± 0.8 | 4.8 | ± 1.2 | 0.155 |
LDL Cholesterol (mmol/L) + | 3.4 | ± 0.7 | 2.8 | ± 1.1 | 0.103 |
HDL Cholesterol (mmol/L) + | 1.2 | ± 0.2 | 1.2 | ± 0.3 | 0.993 |
Triglycerides (mmol/L) + | 1.6 | ± 0.7 | 1.7 | ± 1.0 | 0.712 |
Triglyceride:HDL+ | 1.3 | ± 0.6 | 1.6 | ± 1.4 | 0.543 |
Total Cholesterol (mmol/L)++ | 3.9 | ± 0.8 | 4.2 | ± 1.3 | 0.666 |
LDL Cholesterol (mmol/L)++ | 1.9 | ± 0.3 | 2.3 | ± 1.2 | 0.587 |
HDL Cholesterol (mmol/L)++ | 1.5 | ± 0.7 | 1.1 | ± 0.3 | 0.128 |
Triglycerides (mmol/L)++ | 1.1 | ± 0.3 | 1.9 | ± 1.2 | 0.288 |
Triglyceride: HDL ratio++ | 0.9 | ± 0.5 | 1.8 | ± 1.5 | 0.306 |
Glucose (mmol) | 5.1 | ± 0.5 | 6.6 | ± 2.5 | < 0.001 |
HbA1c (mmol/mol) | 37.8 | ± 3.5 | 46.5 | ± 13.2 | < 0.001 |
Glucose (mmol)* | 5 | ± 0.5 | 5.7 | ± 1.9 | 0.189 |
HbA1c (mmol/mol)* | 36.8 | ± 2.2 | 40.7 | ± 10.5 | 0.201 |
Glucose (mmol)** | 5.6 | ± 0.4 | 7.9 | ± 2.7 | 0.244 |
HbA1c (mmol/mol)** | 44 | ± 4.2 | 53.9 | ± 12.7 | 0.289 |
Weight (kg) | 122.1 | ± 15.3 | 130.2 | ± 27.4 | 0.113 |
Height (m) | 1.61 | ± 0.07 | 1.68 | ± 0.11 | 0.007 |
Waist circumference (cm) | 133.7 | ± 12.8 | 136.3 | ± 18.9 | 0.611 |
BMI (kg/m2) | 47.1 | ± 6.6 | 46 | ± 7.8 | 0.61 |
Functional Capacity (MET max) | 6 | ± 1.7 | 6.1 | ± 2.0 | 0.859 |
Data are presented as means ± standard deviations. |
*Denotes subgroup without diabetes (No Skin tags n = 13, Skin tags n = 50). |
**Denotes subgroup with diabetes (No Skin tags n = 2, Skin tags n = 35). |
+Denotes subgroup not on lipid lowering agent (No Skin tags n = 12, Skin tags n = 52). |
++Denotes subgroup on lipid lowering agent (No Skin tags n = 3, Skin tags n = 33). |
Results from logistic regression analyses, with the presence or absence of any skin tags as the binary dependent variable are shown in Table 2. For every rise of 1 mmHg in SBP, the likelihood of having any skin tags increased by 7.5% (p = 0.005) while patients with hypertension were 5.5 times more likely to have skin tags than patients with normal SBP (p = 0.031). However, the association with hypertension was no longer significant after adjusting for age and sex, both of which had a borderline significant association with skin tag presence, as shown in Table 2. There were non-significant trends to men being 7.6 times more likely than women to have skin tags (p = 0.055) while for every year older, there was a non-significant trend to a 5.1% increase in the likelihood of skin tags (p = 0.067). Similarly, there was a non-significant trend to a 4.55-fold increased likelihood of any skin tags in patients with diabetes compared to those without diabetes (p = 0.055). Those with tags had a higher HbA1c, but not after adjusting for age and sex. The borderline difference observed in the THDLR using the unpaired t-test was not replicated using logistic regression in unadjusted or adjusted analyses.
Table 2
Logistic regression model comparing the influence of various clinical features on the likelihood of having any skin tags versus none, in patients with severe obesity.
Variable | Beta (logit) | S.E. | Exp (Beta) | 95% C.I. | p-value |
Sex | 2.033 | 1.060 | 7.636 | [0.957, | 60.939] | 0.055 |
Age | 0.05 | 0.027 | 1.051 | [0.997, | 1.109] | 0.067 |
Diabetes status | 1.515 | 0.791 | 4.55 | [0.966, | 21.439] | 0.055 |
Diabetes status* | 1.357 | 0.808 | 3.883 | [0.797, | 18.906] | 0.093 |
Hypertension status | 1.707 | 0.790 | 5.511 | [1.171, | 25.929] | 0.031 |
Hypertension status* | 1.316 | 0.822 | 3.728 | [0.745, | 18.666] | 0.109 |
SBP | 0.073 | 0.026 | 1.075 | [1.022, | 1.132] | 0.005 |
SBP* | 0.064 | 0.026 | 1.066 | [1.013, | 1.122] | 0.014 |
HbA1c | 0.107 | 0.05 | 1.113 | [1.01, | 1.227] | 0.031 |
HbA1c* | 0.082 | 0.048 | 1.086 | [0.988, | 1.194] | 0.089 |
THDLR | 0.376 | 0.338 | 1.457 | [0.752, | 2.824] | 0.265 |
THDLR* | 0.271 | 0.313 | 1.311 | [0.71, | 2.418 | 0.387 |
* Adjusted for age and sex. |
Beta is the logit or estimated log odds of having any skin tags for every one unit rise in the variable measure. |
S.E: Standard error for Beta. |
Exp (B) is the exponential of Beta. (So for example for every mmHg rise in systolic blood pressure, there is a 7.5% increased likelihood of having skin tags.) |
C.I: Confidence Interval |
SBP: Systolic Blood Pressure |
THDLR: Triglyceride: HDL-cholesterol ratio. |
In linear regression models with the number of skin tags being the dependent or outcome variable, male sex was strongly associated with skin tags (ß=15.85 [8.61, 23.09], p < 0.001). In other words, men had on average 16 more skin tags than women. There was a borderline statistically significant association between age and skin tags (ß=0.32 [-0.003, 0.63], p = 0.052) such for every ten years older, there were three more skin tags. Similar results to the findings from binary logistic and linear regression analyses were obtained when the number of skin tags was arbitrarily categorized and ordinal regression analyses were conducted (data not shown).
Next, we compared anthropometric and metabolic characteristics in participants with both cervical and axillary skin tags to those who had no skin tags (Supplementary table 1). As before, there were significant differences in glucose and HbA1c, but in addition to SBP, diastolic blood pressure was also elevated and there was a significant difference in weight of 14.8 kg in those with axillary and cervical tags compared to those with none. We compared patients who had axillary skin tags versus those without axillary skin tags, with the only significant difference being greater height and weight in those with axillary skin tags (Supplementary table 2). Finally, we found that compared to patients without cervical skin tags, those with cervical skin tags had higher systolic and diastolic blood pressure, with higher BMI and a (borderline significant) higher waist circumference and weight (Supplementary table 3).