Relationship between thyroid nodules and non-functioning adrenal incidentalomas and their association with insulin resistance

Nonfunctional adrenal adenomas and impaired glucose metabolism: a systematic review and meta-analysis

PURPOSE

Evidence on nonfunctioning adrenal incidentaloma's (NFAI) associated comorbidities and in particular, glucose disorders, is unclear in contrast to adrenal tumors with mild autonomous cortisol secretion. The current systematic review and meta-analysis aimed to assess the burden of impaired glucose metabolism including diabetes mellitus type 2 (T2DM), fasting blood glucose (FBG), and fasting blood insulin (FBI) levels in patients with NFAI and 1-mg overnight dexamethasone suppression test (ODST) ≤ 1.8 μg/dl across published studies.

METHODS

We searched PubMed, Cochrane, and Scopus databases for identifying studies published between 1956 and March 2021. Twenty-five studies met the selection criteria including prospective, retrospective, and case-control studies. Two reviewers independently extracted studies, participants' characteristics and outcome data in a total pooled sample of 1548 patients.

RESULTS

Patients with NFAI had twofold [(odds ratio (OR) (95% confidence interval (CI)): 2.03 (1.39-2.98)] increased odds to present T2DM as well as higher FBG [weighted mean difference (WMD) (95% CI): 3.85 (1.96-5.74)] and homeostasis model assessment (HOMA) [WMD (95% CI): 0.68 (0.23-1.12)] with respect to controls. On the contrary, the WMD of FBI levels did not differ between the two groups. The incidence of T2DM in a subgroup analysis of patients with NFAI without glucose disorders at baseline was 6% [pooled incidence (95% CI): 0.06 (0.04-0.09)].

CONCLUSIONS

Patients with NFAI and 1-mg ODST ≤ 1.8 μg/dl presented higher odds of T2DM and higher levels of FBG and HOMA index than healthy controls.

Prospective role of thyroid disorders in monitoring COVID-19 pandemic

COVID-19 pandemic has affected more than 200 countries and 1.3 million individuals have deceased within eleven months. Intense research on COVID-19 occurrence and prevalence enable us to understand that comorbidities play a crucial role in spread and severity of SARS-CoV-2 infection. Chronic kidney disease, diabetes, respiratory diseases and hypertension are among the various morbidities that are prevalent in symptomatic COVID-19 patients. However, the effect of altered thyroid-driven disorders cannot be ignored. Since thyroid hormone critically coordinate and regulate the major metabolism and biochemical pathways, this review is on the potential role of prevailing thyroid disorders in SARS-CoV-2 infection. Direct link of thyroid hormone with several disorders such as diabetes, vitamin D deficiency, obesity, kidney and liver disorders etc. suggests that the prevailing thyroid conditions may affect SARS-CoV-2 infection. Further, we discuss the oxidative stress-induced aging is associated with the degree of SARS-CoV-2 infection. Importantly, ACE2 protein which facilitates the host-cell entry of SARS-CoV-2 using the spike protein, are highly expressed in individuals with abnormal level of thyroid hormone. Altogether, we report that the malfunction of thyroid hormone synthesis may aggravate SARS-CoV-2 infection and thus monitoring the thyroid hormone may help in understanding the pathogenesis of COVID-19.

Association of Changes in Metabolic Syndrome Status With the Incidence of Thyroid Nodules: A Prospective Study in Chinese Adults

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline (n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years).

Benign Adrenocortical Tumors and the Detection of Nonadrenal Neoplasia

CONTEXT

Patients with adrenocortical tumors have been frequently observed to have nonadrenal neoplasia.

OBJECTIVE

To investigate whether patients with benign adrenocortical tumors have a higher likelihood of having nonadrenal neoplasia detected.

DESIGN AND PARTICIPANTS

Case-control study of patients with benign adrenocortical tumors (cases; n = 400) and normal adrenal glands (controls; n = 400), who underwent repeated abdominal cross-sectional imaging.

MAIN OUTCOMES

Primary analyses: association between case-control status and benign abdominal neoplasia detected via cross-sectional imaging. Secondary analyses: association between case-control status and tumors detected via other imaging modalities.

RESULTS

The mean interval of abdominal imaging was 4.7 (SD = 3.8) years for cases and 5.9 (4.8) years for controls. Cases were more likely to have detected intraductal papillary mucinous neoplasms (IPMNs) of the pancreas (8.5% vs. 4.5%, adjusted OR = 2.22, 95% CI (1.11, 4.63)) compared with controls. In secondary analyses, cases were more likely to have detected thyroid nodules (25.5% vs. 17.0%, adjusted OR = 1.77, 95% CI (1.15, 2.74)), hyperparathyroidism or parathyroid adenomas (3.5% vs. 1.3%, adjusted OR = 3.00, 95% CI (1.00, 11.64)), benign breast masses (6.0% vs. 3.3%, adjusted OR = 3.25, 95% CI (1.28, 8.78)), and benign prostatic hyperplasia (20.5% vs. 5.3%, adjusted OR = 3.20, 95% CI (1.14, 10.60)). Using a composite outcome, cases had higher odds of detection of the composite of IPMN, thyroid nodules, parathyroid tumors, benign breast masses, and prostate hyperplasia (adjusted OR = 2.36, 95% CI: 1.60, 3.50) when compared with controls.

CONCLUSIONS

Patients with benign adrenocortical tumors had higher odds of detected pancreatic IPMN, as well as thyroid nodules, parathyroid tumors, benign breast masses, and prostate hyperplasia compared with patients with normal adrenal glands. These associations may have important implications for patient care and healthcare economics, regardless of whether they reflect incidental discoveries due to imaging detection or frequency bias, or a common risk for developing multiple neoplasia.

Adipocytokines in Non-functional Adrenal Incidentalomas and Relation with Insulin Resistance Parameters

OBJECTIVE

Adrenal incidentalomas are diagnosed incidentally during radiological screenings and require endocrinological investigations for hormonal activity and malignancy. In certain studies, it has been reported that non-functional incidentalomas can be associated with high adipocytokines levels affecting the insulin resistance just like the adipose tissue with metabolic syndrome. Here, we studied serum adipocytokine levels including leptin, resistin, visfatin, omentin 1 and adiponectin in subjects with non-functional adrenal incidentaloma.

METHODS

Seventy-seven (77) patients (Female 57; Male 20) with non-functional adrenal incidentaloma (NFAI) were enrolled in the study. All patients' past medical history, physical examination including Body Mass Index (BMI) and waist circumference were performed. The patients' demographic, radiologic, hormonal and biochemical parameters were recorded. To compare the parameters, a control group (CG) (n=30) was formed from healthy volunteers. Both groups were matched for age, gender, waist circumference and BMI. Serum adipocytokines including leptin, resistin, visfatin, omentin 1 and adiponectin were measured quantitatively by ELISA. Fasting plasma glucose, insulin, sodium, potassium, cortisol, adrenocorticotropic hormone (ACTH), lipid profiles, and dehidroepiandrostenedion sulphate (DHEAS) were measured.

RESULTS

Mean age of the patients was 52.2±10.4 years. BMI and waist circumference of NFAI patients were 26.2±3.28 kg/m2 and 90.2 ±7.5cm, respectively. The mean age of the control group was 48.0±8.16. BMI and waist circumference values for the control group were 25.3±3.5 kg/m2 and 88.3±9.6 cm, respectively. When both groups were compared for age, gender, BMI and waist circumference were non-significant (p>0.05). Serum fasting insulin, total cholesterol, LDL, triglyceride levels of the NFAI group were significantly higher than CG (p<0.05). The insulin resistance index (HOMAIR) values of the NFAI subjects were found to be higher than CG (2.5±1.37, 1.1±0.3 p=0.00). Resistin level of NFAI group was also found to be higher than CG [286.6 ng/L vs. 197 ng/L; (P=0,00)], respectively. Leptin levels of NFAI were significantly higher than CG [441.1 ng/mL vs. 186.5 ng/mL; (P=0.00)] respectively. Adiponectin levels were significantly reduced in the NFAI group than in the CG [10.7 mg/L vs. 30.8 mg/L; (P=0.00)]. Comparision of visfatin and omentin levels was nonsignificant.

CONCLUSION

In this study on subjects with non-functional adrenal incidentaloma, we found not only significantly decreased serum adiponectin levels but also increased leptin, resistin levels as well as dyslipidemia, hypertension and high insulin resistance index. All of which could affect insulin resistance and cardiovascular risk factors. The underlying mechanisms of these findings are unknown, hence further studies are needed.

The Role of Insulin Resistance/Hyperinsulinism on the Rising Trend of Thyroid and Adrenal Nodular Disease in the Current Environment

Thyroid follicular cells, as well as adrenocortical cells, are endowed by an intrinsic heterogeneity regarding their growth potential, in response to various stimuli. This heterogeneity appears to constitute the underlying cause for the focal cell hyperplasia and eventually the formation of thyroid and adrenal nodules, under the influence of growth stimulatory factors. Among the main stimulatory factors are the pituitary tropic hormones, thyroid-stimulating hormone (TSH) or thyrotropin and adrenocorticotropic hormone (ACTH), which regulate the growth and function of their respective target cells, and the insulin/insulin-like growth factor system, that, through its mitogenic effects, can stimulate the proliferation of these cells. The predominance of one or the other of these growth stimulatory factors appears to determine the natural history of thyroid and adrenal nodular disease. Thus, iodine deficiency was, in the past, the main pathogenic factor responsible, through a transient rise in TSH secretion, for the endemic nodular goiter with the characteristic colloid thyroid nodules among the inhabitants in iodine deficient areas. The correction of iodine deficiency was followed by the elimination of endemic colloid goiter and the emergence of thyroid autoimmunity. The recent epidemic of obesity and metabolic syndrome (MS), or insulin resistance syndrome, has been associated with the re-emergence of nodular thyroid disease. A parallel rise in the incidence of benign, nonfunctional adrenocortical tumors, known as adrenal incidentalomas, has also been reported in association with the manifestations of the MS. It is likely that the compensatory to insulin resistance hyperinsulinemia may be responsible for the rising trend of thyroid and adrenal nodular disease in the current environment.