Of the 30 patients included in the study group, 18 (60%) were female and 12 (40%) were male. The age of patients with acrochordon ranged between 21-66 years, with a mean age of 48.17 ± 12.08 years. The control group consisted of 17 women (56.7%) and 13 men (43.3%). The age of the control group ranged between 18-77 years and the mean age was 48.37 ± 13.81 years. There was no statistically significant difference between the two groups in terms of age and sex distribution (p = 0.953 and p = 0.793, respectively). The disease duration of the group with acrochordon ranged from 1 to 35 years, with a mean duration of 7.9 ± 7.07 years (min- max = 1-35 years, median = 5 years). Twenty-three of the patients with acrochordon had multiple locations. Twelve (40%) of the patients had acrochordon lesions in axillary and neck locations, 3 (10%) patients had in axillary region, neck and on trunk, 2 (6.6%) patients had on trunk, neck, and face, 2 (6.6%) patients had on the neck, infra-mammarian region and extremities, 1 (3.3%) patient had in axillary region, neck and extremities, 1 (3.3%) patient had on the neck and face, and 1 (3.3%) patient had on the axilla and the trunk.
BMI values of the group with acrochordon ranged from 22.2 kg / m2 to 48.1 kg / m2, with a mean value of 30.55 ± 5.09 kg / m2. BMI values of the control group were between 18.6-42.6 kg / m2 and the mean was 28.17 ± 6.19 kg / m2. According to BMI values in the acrochordon group; 3 patients (10%) were normal, 13 (43.3%) were overweight and 14 (46.7%) were obese. Of the control group, 11 (36.7%) were normal, 8 (26.7%) were overweight and 11 (36.7%) were obese. The mean BMI of the study group with acrochordon was significantly higher than that of the control group (p = 0.04). There was no significant correlation between the current acrochordon count and BMI value of the patient group (p = 0.206).
When we examined the fasting blood glucose (FBG) level of the patient group, there were normal values in 19 patients (63.3%), whereas 9 (30%) patients had impaired FBG levels and 2 patients (6.7%) had FBG levels within DM range. Ten (33.3%) subjects in the control group had normal FBG levels, whereas 17 (56.7%) had impaired FBG levels and 3 (10%) had FBG levels within DM range. The difference in FBG category distribution between groups did not reach statistical significance (p=0.06).
According to the OGTT results, 22 (73.3%) patients in the acrochordon group were normoglycemic (below 140 mg/dL), while 5 (16.7%) patients had impaired glucose tolerance (IGT) (140-200 mg/dL) result and 3 had DM (over 200 mg/dL) diagnosis. In the control group, 15 (50%) subjects were within normoglycemic ranges, 8 (26.7%) patients had IGT and 7 (23.3%) patients had DM diagnosis. There was no statistically significant difference between the groups regarding the OGTT results (p = 0.16).
Patients with acrochordon were divided into two groups according to the lesion count; those with fewer than 15 lesions and those with 15 or more. There was no statistically significant difference in carbohydrate metabolism between these two groups. In addition, there was no statistically significant relationship between carbohydrate metabolism and acrochordon location (p>0.05).
The mean HbA1c value was 5.83 ± 0.62% in the group with acrochordon and 6.06 ± 0.67 % in the control group (p = 0.037).The mean serum insulin level was 13.87 ± 12.53 uU / ml in the group with acrochordon and 10.45 ± 9.61 uU / ml in the control group (p = 0.031). According to the HOMA-IR values of the participants, 17 patients (56.7%) in the study group had insulin resistance and 13 patients (43.3%) did not. In the control group, 10 subjects (33.3%) had insulin resistance while 20 (66.7%) did not. The mean HOMA-IR value of the study group was tended to be higher compared to the controls (p=0.069). In addition, insulin resistance was found in 9 of 14 obese patients (64.28%) in the acrochordon group and in 5 (35.71%) of 11 obese patients in the control group. There was no significant difference between the groups in terms of insulin resistance ratio in obese patients (p = 0.34). There was no significant correlation between HOMA-IR value and acrochordon count (p = 0.547). No relation was found between HOMA- IR value and acrochordon localization (p>0.05).
There was no statistically significant difference between the control group and acrochordon group in terms of triglyceride, total cholesterol, VLDL, HDL, LDL cholesterol levels and total cholesterol/HDL and LDL/HDL ratios (p>0.05, for all). There was no statistically significant relation of lipid profile with the number and location of acrochordon lesions (p>0.05). The mean serum free fatty acid level was 0.53 ± 0.17 mmol / L in the acrochordon group and 0.49 ± 0.22 mmol / L in the control group. There was no statistically significant difference in serum free fatty acid levels between the study groups (p = 0.228).
The mean serum leptin level was 11228.97 ± 4.56 pg / ml in the acrochordon group and 9970.30 ± 4.49 pg / ml in the control group. There was no statistically significant difference in serum leptin levels between the study groups (p = 0.352).
The mean serum IGF-1 value was 63.89 ± 40.96 ng / ml in the acrochordon group and 92.3 ±73.98 ng / ml in the control group. The difference between the groups in terms of mean serum IGF-1 level was not significant statistically (p=0.193) In addition, there was no significant correlation between serum IGF-1 level and acrochordon count (p = 0.671). Serum IGF-1 levels were not significantly different in normoglycemic patients with acrochordon compared to the control group (p = 0.125).
IGF-1R staining was observed in 29 of 30 patients in the group with acrochordon. Pathologic specimens of 12 patients (40%) were mildly stained (+), 14 (46.7) were moderately stained (++) and 3 (10%) were intensely stained (+++). Only 5 (16.7%) of the control group had mild (+) staining, and 25 (83.3%) had no staining (-).
Negative IGF-1R staining in normal tissue is shown in Figure 1a, IGF-1R with mild (+), moderate (++) and severe (+++) staining in Figure 1b, 1c and 1d, respectively.
Presence of IGF-1R was significantly higher in the acrochordon group compared to the control group (p <0.001). The distribution of IGF-1R staining levels according to groups is shown in Table 1.
Table 1. The distribution of IGF-1R staining levels according to groups
|
No staining (-)
n (%)
|
Mild (+)
n (%)
|
Moderate
(++) n (%)
|
Intense (+++)
n (%)
|
Patients
|
1 (3.3)
|
12 (40)
|
14 (46.7)
|
3 (10)
|
Controls
|
25 (83.3)
|
5 (16.7)
|
0 (0)
|
0 (0)
|
When the IGF-2R staining levels were examined in the acrochordon group, staining was observed in all patients. One patient (3.3%) had mild (+) staining, 5 (16.7) had moderate (++) staining, and 24 (80%) had intense (+++) staining. Mild (+) staining was present in only 6 (20%) of the control group and 24 (80%) of them had no staining observed in the control group. Mild (+), moderate (++) and intense (++) staining with IGF-2R in acrochordon tissue are shown in Figure 2.
IGF-2R staining was significantly higher in the acrochordon group than the control group (p<0.001). The distribution of IGF-2R staining levels according to groups is shown in Table 2.
Table 2. The distribution of IGF-2R staining levels according to groups
|
No staining (-)
n (%)
|
Mild (+)
n (%)
|
Moderate
(++) n (%)
|
Intense (+++)
n (%)
|
Patients
|
-
|
1 (3,3)
|
5 (16,7)
|
24 (80)
|
Controls
|
24 (80)
|
6 (20)
|
-
|
-
|
There was a positive correlation between IGF-1R staining intensity and serum IGF-1 level in patients with acrochordon (r = 0.028, p = 0.003). However, there was no statistically significant correlation between IGF-2R staining intensity and serum IGF-1 level (p = 0.11).
There was a positive correlation between IGF-1R staining intensity and BMI in patients with acrochordon (r = 0.257, p = 0.048). The relationship between IGF-1R level and BMI is shown in Table 3.
Table 3. Relationship between IGF-1R level and BMI
|
IGF-1R
|
Total n (%)
|
Staining positive
n (%)
|
No staining
n (%)
|
Normal
|
4 (28.6)
|
10 (71.4)
|
14 (100)
|
Overweight
|
14 (66.7)
|
7 (33.3)
|
21 (100)
|
Obese
|
16 (64)
|
9 (36)
|
25 (100)
|
Total
|
34 (56.7)
|
26 (43.3)
|
60 (100)
|
There was a positive correlation between IGF-2R staining and BMI (r = 0.357, p = 0.003). In addition, the IGF-2R staining intensity is significanly correlated with BMI (r = 0.375, p = 0.003) There was no correlation between IGF-1R or IGF-2R with age and lesion duration in patients with acrochordon (p> 0.05, for all).
There was no relationship between IGF-1R staining and the number and localization of acrochordons (p = 1.00). In addition, there was no correlation between the intensity of IGF- 1R staining and the number of acrochordons (p = 0.423). There was no significant correlation between IGF-1R staining intensity and insulin level (p = 0.166). Whereas, there was a positive correlation between IGF-2R staining intensity and serum insulin levels (r = 0.27, p = 0.037). Meanwhile, there was no correlation between the number of lesions and IGF-2R staining intensity (p = 0.352).
There was no statistically significant difference between the patients with normal serum insulin levels and the control group in terms of IGF-1R and IGF-2R staining (p = 1.00).
The levels of IGF-1R and IGF-2R were similar between genders (p = 0.93 and p = 0.593, respectively).
There was no statistically significant difference between the patients with acrochordon and the control group in terms of HOMA-IR and staining with IGF-1R and IGF-2R (p = 0.438 and p = 0.459). In addition, HOMA-IR level was not correlated with IGF-1R and IGF-2R staining intensity (p>0.05, for both).
The staining with IGF-1R and IGF-2R was significantly higher in the normoglycemic patients with acrochordon compared to the control group (p <0.01).
In logistic regression analysis, independent factors were investigated associated with the presence of acrochordon. None of the variables included in the model (BMI, serum insulin levels, IGF-1R and IGF-2R staining) were found to be independently associated with the presence of acrochordon (Table 4)
Table 4. Logistic regression analysis results of the potential factors associated with the presence of acrochordon
|
p value
|
%95 Confidence interval
|
Upper limit
|
Lower limit
|
BMI
|
0.743
|
0.827
|
1.306
|
IGF-1R
|
0.337
|
0.175
|
162.59
|
IGF-2R
|
0.996
|
0
|
|
Insulin
|
0.179
|
0.554
|
1.11
|
In the logistic regression analysis we found that HOMA-IR, insulin and serum IGF-1 are independent variables associated with IGF-1R staining. (Table 5)
In the logistic regression model of BMI, serum IGF-1, serum insulin, and HOMA-IR as independent variables which may affect IGF-2R staining. (Table 6)
Table 5. The logistic regression analysis of independent variables associated with IGF-1R staining
|
p value
|
%95 Confidence interval
|
Upper limit
|
Lower limit
|
HOMA-IR
|
0.021
|
0.027
|
0.749
|
BMI
|
0.314
|
0.945
|
1.191
|
Insulin
|
0.020
|
1.100
|
2.987
|
IGF-1
|
0.032
|
0.976
|
0.999
|
Table 6. Logistic regression analysis of independent variables associated with IGF-2R staining
|
p value
|
%95 Confidence interval
|
Upper limit
|
Lower limit
|
HOMA-IR
|
0.023
|
0.023
|
0.758
|
BMI
|
0.084
|
0.985
|
1.275
|
Insulin
|
0.022
|
1.091
|
3.114
|
IGF-1
|
0.039
|
0.977
|
0.999
|