Elastography detected solid organ stiffness increased in patients with acromegaly

Abstract

Elastography is a method to examine the increase in solid organs stiffness (SOS), and there is no data in the literature regarding to its use in patients with acromegaly. In this study, we aimed to investigate the change of SOS in patients with acromegaly and to determine the parameters closely related to SOS in same patient groups.We included 40 subjects with acromegaly and 40 healthy control subjects. In addition to routine renal, liver and thyroid ultrasonography (USG), SOS for 3 solid organs were measured by elastography. The participants of the study were divided into 3 groups as the control (Group-I), acromegaly patients with remission (Group-II), and acromegaly patients without remission (Group-III).Insulin growth factor-1 (IGF-1) level significantly increased from Group-I to Group-III. Glucose, creatinine, albuminuria, alkaline phosphatase, TSH, and growth factor levels were highest in Group-III and statistically significance was found only between Group-I and Group-III. Liver, kidney and thyroid size and echogenicity were increased from Group-I to Group-III. Liver and renal stiffness and thyroid gland strain ratio significantly increased from Group-I to Group-III and these parameters were statistically different between all groups. In linear regression analysis, IGF-1 levels were independent determinants of SOS.SOS values of acromegaly patients with active disease were significantly increased compared to both the control group and the acromegaly patients in remission phase. Serum IGF-1 levels were independently associated with SOS in these patients. SOS measurement should be part of a routine USG examination in patients with acromegaly, especially in patients during active disease.

Figure 1

Renal cortical stiffness measurement by point shear wave elastography (A) normal renal cortical stiffness as 2.72 ± 1.08 kPa in control subject. (B) Increased renal cortical stiffness as 6.21 ± 3.29 kPa in patients with acromegaly with remission. (C) Significantly increased renal cortical stiffness as 17.56 ± 11.46 kPa in patients with acromegaly during active disease.

Figure 2

Liver stiffness measurement by point shear wave elastography. (A) Normal liver stiffness measurement as 1.14 ± 0.31 kPa in control subjects. (B) Increased liver stiffness measurement as 8.15 ± 2.50 kPa in patients with acromegaly with remission. (C) Significantly increased liver stiffness measurement as 11.67 ± 2.76 kPa in patients with acromegaly during active disease.

Figure 3

Thyroid gland strain ratio measurement by strain elastography. The first region of interest (ROI) (strain 1) was placed in the reference muscle tissue, and the other ROI was placed on the thyroid gland (strain 2). (A) The strain ratio was calculated as 0.76 and elastography color grades of the thyroid gland grade 3; blue (soft tissue) in control subjects. (B) The strain ratio was calculated as 1.12 and elastography color grades of the thyroid gland grade 2: green (intermediate tissue) in Acromegaly patient with remission. (C) The strain ratio was calculated as 1.78 and elastography color grades of the thyroid gland grade 1: red to yellow (hardest or hard tissue) in Acromegaly patient during active disease. ROI = region of interest.

Figure 4

There is significant correlation between IGF-1 and (A) renal cortical stiffness, (B) liver stiffness and (C) thyroid stiffness or thyroid gland strain ratio.