ABSTRACT

Background: Diabetes mellitus and thyroid dysfunction are two of the most prevalent endocrine disorders across globe, and concurrence of them may cause worsening metabolic control and increased morbidity. Thyroid hormone changes differ among types of diabetes, gender, and related biochemical derangements.
Objective: Aim This study was to assess the thyroid function and frequency of thyroid dysfunction in type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) patients compare to non-diabetic clinic controls.
Methods: It is a case-control study carried on two hundred participants, from them one hundred controls and one hundred patient in the Diabetes Center in Al-Sadr General Hospital in Najaf Al-Ashraf in the period from May 2025 to August 2025. This study consisted of 50 patients of type 1 diabetes mellitus, 50 patients of type 2 diabetes mellitus and 100 non- diabetic controls. Thyroid function was determined by serum levels of thyroid-stimulating hormone, free triiodothyronine and free thyroxine. Furthermore, laboratory investigations such as fasting blood glucose, postprandial blood glucose, glycated hemoglobin, lipid Profile, serum urea, creatinine and urinary microalbumin were studied by standard laboratory techniques.
Results: Of the groups studied, thyroid hormone levels differed significantly. In patients with type 2 diabetes mellitus, thyroid-stimulating hormone was elevated and free triiodothyronine and free thyroxine levels were reduced to a greater degree in females, indicating a more hypothyroid pattern. In comparison, at the opposite end of the spectrum, type 1 diabetes mellitus patients had higher free thyroid hormone levels (specifically FT3 and FT4) and lower TSH values, suggesting the potential for hyperthyroid function to be a problem. About half of the patients with type 2 diabetes mellitus (more frequently females) had a higher prevalence of hypothyroidism, while the frequency of hyperthyroidism was greater in females with type 1 diabetes mellitus. Patients with diabetes also showed a significantly higher fasting blood glucose, postprandial blood glucose, glycated hemoglobin and lipid profile disorders compared with the controls.
Conclusions: The results show that thyroid function is profoundly altered in diabetic patients, being that differences are presented regarding type 1 and type 2 diabetes. Hypothyroid changes were more often associated with type 2 diabetes mellitus, especially in females, whereas type 1 diabetes mellitus was associated with a trend towards hyperthyroid changes. In conclusion, routine thyroid function screening is clinically useful to facilitate case finding for early diagnosis and better disease management in diabetic patients.

kEYWORDS

Diabetes mellitus; Type 1 diabetes; Type 2 diabetes; Thyroid dysfunction; TSH; FT3; FT4; Hypothyroidism; Hyperthyroidism.

REFERENCES

1) American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes—2025. Diabetes Care. 2025;48(Suppl 1):S1-S200.
2) World Health Organization. Classification of diabetes mellitus. Geneva: WHO; 2019.
3) Chaker L, Bianco AC, Jonklaas J, Peeters RP. Hypothyroidism. Lancet. 2017;390(10101):1550-1562.
4) Vanderpump MPJ. The epidemiology of thyroid disease. Br Med Bull. 2011;99:39-51.
5) Biondi B, Kahaly GJ, Robertson RP. Thyroid dysfunction and diabetes mellitus: two closely associated disorders. Endocr Rev. 2019;40(3):789-824.
6) Eom YS, Wilson JR, Bernet VJ. Links between thyroid disorders and glucose homeostasis. Diabetes Metab J. 2022;46(2):239-256.
7) Brenta G. Diabetes and thyroid disorders. Prog Cardiovasc Dis. 2019;62(3):258-264.
8) Kahaly GJ, Hansen MP. Type 1 diabetes associated autoimmunity. Autoimmun Rev. 2016;15(7):644-648.
9) Frommer L, Kahaly GJ. Type 1 diabetes and autoimmune thyroid disease—the genetic link. Front Endocrinol (Lausanne). 2021;12:618213.
10) Dimitriadis G, Mitrou P, Lambadiari V, Maratou E, Raptis SA. Insulin action in adipose tissue and muscle in hypothyroidism and hyperthyroidism. Endocr Rev. 2020;41(2):bnaa001.
11) Hage M, Zantout MS, Azar ST. Thyroid disorders and diabetes mellitus. J Thyroid Res. 2011;2011:439463.
12) Papazafiropoulou A, Sotiropoulos A, Kokolaki A, et al. Prevalence of thyroid dysfunction among Greek type 2 diabetic patients. J Clin Med Res. 2010;2(2):75-78.
13) Radaideh AR, Nusier MK, Amari FL, et al. Thyroid dysfunction in patients with type 2 diabetes mellitus in Jordan. Saudi Med J. 2004;25(8):1046-1050.
14) Taskinen MR. Diabetic dyslipidaemia: from basic research to clinical practice. Lancet. 2003;362(9385):429-436.
15) Ginsberg HN. Insulin resistance and cardiovascular disease. Circulation. 2001;103(6):792-797.
16) Schleicher E, Gerdes C, Petersmann A, et al. Definition, classification and diagnosis of diabetes mellitus. Exp Clin Endocrinol Diabetes. 2022;130(S01):1-8.
17) Iwakura H, Matsumoto Y, Nakatani Y, et al. Association of thyroid function with glycemic control and diabetic nephropathy in patients with type 2 diabetes mellitus. BMC Endocr Disord. 2023;23:114.
18) Alreshidi NF, Alqahtani AS, Alshammari AM, et al. Relationship of thyroid dysfunction and its manifestations in patients with diabetes mellitus. Eur Rev Med Pharmacol Sci. 2024;28:2263-2271.
19) Biondi B, Cooper DS. The clinical significance of subclinical thyroid dysfunction. Lancet. 2012;379(9821):1142-1154.
20) Jimoh A, Ghazali M, Ogundeji O, et al. Spectrum of thyroid function test among type 2 diabetic patients. SAGE Open Med. 2022;10:20503121221097625.
21) Ray S, Ghosh S. Thyroid disorders and diabetes mellitus: double trouble. J Diabetes Res Ther. 2016;2:1-7.
22) Alo K, Banik S, Ahammed S, et al. Study of thyroid function status in type 2 diabetic patients. KYAMC J. 2019;10(2):95-98.
23) Rousset B, Dupuy C, Miot F, Dumont J. Thyroid hormone synthesis and secretion. Endotext. 2015.
24) Chaker L, Wolters FJ, Bos D, et al. Thyroid function and risk of type 2 diabetes: a population-based prospective cohort study. BMC Med. 2016;14:150.
25) Taylor PN, Albrecht D, Scholz A, et al. Global epidemiology of hyperthyroidism and hypothyroidism. Nat Rev Endocrinol. 2018;14:301-316.

Cite this article

Hatem, Z. M. (2026). Thyroid Dysfunction, Remodeling, and Trends in Dysfunctional Thyroid Between People with Diabetes Mellitus Type 1 And Type 2. INTERNATIONAL JOURNAL OF HEALTH & MEDICAL RESEARCH, 5(5), 451-456. https://doi.org/10.58806/ijhmr.2026.v5i5n17