We collected data from 44 healthy subjects and 44 patients with AIs [NFAI (n = 32) and PACS (n = 12)]. Clinical and biochemical data of patients with AIs in comparison with healthy subjects are included in Table 1.
Table 1
Baseline characteristics of healthy controls and patients with AIs.
Variable | AI patients (n = 44) | Healthy controls (n = 44) | p-value |
Sex : M/F [n (%)] | 13 (29.5%)/31 (70.5%) | 13 (29.5%)/31 (70.5%) | 0.99 |
Age (mean ± SD) Years | 64 ± 9.1 | 63.4 ± 9.1 | 0.78 |
BMI [median (IQR)] kg/m2 | 27.7 (9.7) | 27.9 (7.2) | 0.48 |
Hypertension [n (%)] | 21 (47.7%) | 17 (38.6%) | 0.39 |
Dyslipidemia [n (%)] | 20 (45.5%) | 22 (50%) | 0.67 |
Prediabetes/DM2 [n (%)] | 15 (34.1%) | 19 (43.2%) | 0.12 |
Osteopenia/osteoporosis [n (%)] | 11 (25%) | 7 (15.9%) | 0.11 |
Bilateral AIs [n (%)] | 11 (25%) | na | na |
Size of AI [median (IQR)] mma | 15 (16.5) | na | na |
Serum F (mean ± SD) µg/dL | 15.7 ± 5.2 | 16.1 ± 6.2 b | 0.75 |
ACTH [median (IQR)] pg/mL | 16.1 (14.1) | 23.1 (20.3) c | 0.12 |
Post-ODST F [median (IQR)] µg/dL | 1.5 (0.7) | 0.9 (0.4) d | < 0.001 |
UFC [median (IQR)] µg/24h | 62.7 (120.1) | 57.1 (81) e | 0.29 |
DHEA-S [median (IQR)] µg/dL | 56.9 (76.6) | 150 (200.3) e | 0.04 |
Hair F [median (IQR)] pg/mg | 115.43 (41.29) | 103.49 (35.82) | 0.47 |
Hair AEA [median (IQR)] pg/mg | 3.23 (1.62) | 5.12 (1.25) | < 0.001 |
Hair 2-AG [median (IQR)] pg/mg | 35.16 (22.28) | 51.49 (17.82) | 0.002 |
a The size of the AIs was defined as the maximal axial diameter on CT. If bilateral AI, the size of the largest AI is given.b Available in 24 controls. c Available in 22 controls. d Available in 25 controls. e Available in 15 controls.
Abbreviations: AI: adrenal incidentaloma, M: male, F: female, na: not applicable, BMI: Body Mass Index, DM2: Diabetes Mellitus type 2, SD: standard deviation, IQR: interquartile range, F: cortisol level, ACTH: adrenocorticotropic hormone, ODST: 1-mg overnight dexamethasone suppression test; UFC, 24-hour urinary free cortisol, DHEA-S: dehydroepiandrosterone sulfate, AEA: anandamide, 2-AG: 2-arachidonoylglycerol.
Τhe prevalence of hypertension (47.7 vs 38.6%), dyslipidemia (45.5 vs 50%), prediabetes/DM2 (34.1 vs 43.2%) and osteopenia/osteoporosis (25 vs 15.9%) as well as the median body mass index (BMI) (27.7 vs 27.9 kg/m2) did not differ statistically significantly between the 2 groups (patients with AIs vs controls). Median serum DHEA-S levels were significantly lower in patients with AIs in comparison with healthy controls (56.9 vs. 150 μg/dL, p =0.04). However, no difference in baseline morning (8.00 am) levels of serum F (mean±SD: 15.7±5.2 vs 16.1±6.2 μg/dL), median levels of ACTH (16.1 vs 23.1 pg/mL) and UFC (62.7 vs 57.1 μg/24h) was found between AI group and healthy subjects.
No significant statistical difference was observed in the median levels of hair F between patients with AIs and controls (115.43 vs 103.49 pg/mg, p=0.47 respectively). However, the median levels of hair AEA and 2-AG were found significantly decreased in patients with AIs compared to controls (AEA:3.23 vs 5.12 pg/mg and 2-AG:35.16 vs 51.49 pg/mg, p<0.001 and p=0.002 respectively).
The baseline characteristics of the 3 subgroups of the study population (patients with NFAI, patients with PACS, healthy subjects) are included in Table 2.
Table 2. Baseline characteristics of patients with NFAIs and PACS comparing with healthy controls.
Variable
|
NFAI
(n=32)
|
PACS
(n=12)
|
Healthy controls (n=44)
|
p-value (NFAI vs controls, PACS vs controls, NFAI vs PACS)
|
Sex: M/F
[n (%)]
|
9 (28.1%)/23 (71.9%)
|
4 (33.3%)/8 (66.7%)
|
13(29.5%)/31
(70.5%)
|
0.89, 0.8, 0.74
|
Age (mean±SD)
Years
|
64.1±8.8
|
63.6±10.3
|
63.4±9.1
|
0.94, 0.99, 0.98
|
BMI (mean±SD)
kg/m2
|
28.1±5.2
|
26.4±9.9
|
29.2±6.1
|
0.77, 0.4, 0.72
|
Hypertension [n (%)]
|
13 (40.6%)
|
8 (66.7%)
|
17 (38.6%)
|
0.86, 0.08, 0.12
|
Dyslipidemia [n (%)]
|
14 (43.8%)
|
6 (50%)
|
22 (50%)
|
0.59, 0.99, 0.71
|
Prediabetes/DM2 [n (%)]
|
10 (31.3%)
|
5 (41.7%)
|
19 (43.2%)
|
0.18, 0.54, 0.52
|
Osteopenia/Osteoporosis [n (%)]
|
8 (25%)
|
3 (25%)
|
7 (15.9%)
|
0.16, 0.39, 0.99
|
Bilateral AIs [n (%)]
|
6 (18.8%)
|
5 (41.7%)
|
na
|
0.12
|
Size of AIsa [median (IQR)]
Mm
|
13 (10.25)
|
24.5 (30)
|
na
|
0.01
|
Serum F (mean±SD)
μg/dL
|
15.7±5
|
15.6±6
|
16.1 ±6.2 b
|
0.96, 0.97, 0.99
|
ACTH [median (IQR)]
pg/mL
|
17.4 (13.6)
|
14.5 (15.4)
|
23.1 (20.3) c
|
0.74, 0.25, 0.99
|
Post-ODST F [median (IQR)]
μg/dL
|
1.4 (0.5)
|
2.1 (1.4)
|
0.9 (0.4) d
|
0.034, <0.001, <0.001
|
UFC [median (IQR)]
μg/24h
|
55 (97.5)
|
120 (25.8)
|
57.1 (81) e
|
0.99, 0.25, 0.45
|
DHEA-S [median (IQR)]
μg/dL
|
60 (78.3)
|
42.1 (44.2)
|
150 (200.3) e
|
0.42, 0.03, 0.33
|
Hair F [median (IQR)]
pg/mg
|
104.5(49.75)
|
118.4(22.88)
|
103.5(35.82)
|
0.99, 0.378, 0.487
|
Hair AEA [median (IQR)]
pg/mg
|
3.43 (1.62)
|
3.23(1.44)
|
5.12(1.25)
|
<0.001, 0.002, 0.99
|
Hair 2-AG [median (IQR)]
pg/mg
|
36.64(26.24)
|
31.69(13.61)
|
51.49(17.82)
|
0.038, 0.02, 0.99
|
aThe size of the AIs was defined as the maximal axial diameter on CT. If bilateral AI, the size of the largest AI is given. bAvailable in 24 controls. c Available in 22 controls. dAvailable in 25 controls. eAvailable in 15 controls.
Abbreviations: NFAI: non-functioning adrenal incidentaloma, PACS: possible autonomous cortisol secretion, M: male, F: female, na: not applicable, BMI: Body Mass Index, DM2: Diabetes Mellitus type 2, SD: standard deviation, IQR: interquartile range, F: cortisol level, ACTH: adrenocorticotropic hormone, ODST: 1-mg overnight dexamethasone suppression test, UFC: 24-hour urinary free cortisol, DHEA-S: dehydroepiandrosterone sulfate, AEA: anandamide, 2-AG: 2-arachidonoylglycerol.
There was no difference between the 3 groups (NFAI group vs PACS group vs control group) regarding the metabolic status, as defined by the mean BMI (28.1±5.2 vs 26.4±9.9 vs 29.2±6.1 kg/m2), the prevalence of hypertension (40.6 vs 66.7 vs 38.6%), dyslipidemia (43.8 vs 50 vs 50%) and prediabetes/DM2 (31.3 vs 41.7 vs 43.2%). The prevalence of bone disease did not differ between the groups (25 vs 25 vs 15.9%), as well. The median maximal AI diameter was greater in patients with versus without PACS (24.5 vs 13 mm, p=0.01). No difference in the levels of serum F, ACTH and UFC was observed between the studied groups, except for the median F levels post-ODST which were significantly increased in PACS group compared to NFAI group or controls as well as between NFAI group and controls (2.1 vs 1.4 vs 0.9 μg/dl, pNFAI-PACS<0.001, pPACS-control<0.001, pNFAI-control=0.034). In addition, median serum DHEA-S levels were significantly decreased in the PACS group as compared to control group (42.1 vs 150 μg/dl, p=0.03).
The median hair F levels were found similar among the studied subgroups (104.5 vs 118.4 vs 103.5 pg/mg). Significantly decreased median levels of hair AEA and 2-AG were found in patients with NFAIs compared to controls (AEA: 3.43 vs 5.12 pg/mg and 2-AG: 36.64 vs 51.49 pg/mg, p<0.001 and p=0.038 respectively) as well as in patients with PACS compared to controls (3.23 vs 5.12 pg/mg and 31.69 vs 51.49 pg/mg, p=0.002 and p=0.02 respectively) (Figure 1). Among the patients with AIs, median levels of ECs were found lower in PACS group compared to NFAI, although not statistically significantly (AEA: 3.23 vs 3.34 pg/mg and 2-AG: 31.69 vs 36.64 pg/mg).
Correlation analysis indicated a significantly negative association of the hair AEA and post-ODST F levels (rs=-0.257, p=0.033) (Figure 2). No significant correlation was found between the hair AEA and 2-AG levels with the hair F, baseline morning F, ACTH, DHEA-S or UFC levels.