TSH oscillations in young patients with type 1 diabetes may be due to glycemic variability
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A relationship between thyroid dysfunction and diabetes mellitus has been described by several authors but the role of glycemic variability is still unclear. We planned the present study to evaluate the influence of glycemic variability on thyroid hormones and TSH concentrations in patients with type 1 diabetes mellitus (T1DM).
Seventy-seven young patients with T1DM were enrolled and evaluated for basal glucose concentrations, HbA1c, thyroid hormones and TSH concentrations. Glucose variability was investigated by considering the standard deviation of blood glucose readings and by calculating the mean amplitude of glycemic excursions and continuous overlapping net glycemic action (CONGA). The low (LBGI) and high (HBGI) blood glucose indices were also calculated. The correlations between TSH, thyroid hormones, glycemia and HbA1c were studied in patients and in controls, whereas those between TSH, thyroid hormones and indices of glucose variability only in patients.
No correlations were observed in T1DM patients between free thyroid hormones and glycemic values, HbA1c and indices of glucose variability, while an inverse correlation was observed between TSH levels and glycemic values (r = −0.27; p = 0.01), CONGA index (r = −0.35; p = 0.001) and HBGI (r = −0.28; p = 0.01) but not with HbA1c (r = −0.1; p = 0.47).
Our results suggest a direct action of glycemic excursions on TSH secretion, regardless of variations of thyroid hormone concentrations. Thus, the evaluation of thyroid function through the assay of TSH concentrations in these patients should be made, if possible, by multiple samples on patients in euglycemic state to avoid underestimation or overestimation of thyroid dysfunction due to a wrong diagnosis of euthyroidism or dysthyroidism with consequent inappropriate choice of therapeutic options.
KeywordsTSH Type 1 diabetes Glycemic variability CONGA MAGE LBGI
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in the study were in accordance with the ethical standards of institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 8.Korevaar TI, Nieboer D, Bisschop PH, Goddijn M, Medici M, Chaker L, de Rijke YB, Jaddoe VW, Visser TJ, Steyerberg EW, Tiemeier H, Vrijkotte TG, Peeters RP (2016) Risk factors and a clinical prediction model for low maternal thyroid function during early pregnancy: two population-based prospective cohort studies. Clin Endocrinol 85:902–909CrossRefGoogle Scholar
- 15.Gürsoy N, Ercan TE, Ertürk E, Imamoglu S, Annik A (1999) The relationship between the glycemic control and the hypothalamus-pituitary-thyroid axis in diabetic patients. Turk J Endocrinol Metab 4:163–168Google Scholar
- 16.Palmer SC, Mavridis D, Nicolucci A, Johnson DW, Tonelli M, Craig JC, Maggo J, Gray V, De Berardis G, Ruospo M, Natale P, Saglimbene V, Badve SV, Cho Y, Nadeau-Fredette AC, Burke M, Faruque L, Lloyd A, Ahmad N, Liu Y, Tiv S, Wiebe N, Strippoli GF (2016) Comparison of clinical outcomes and adverse events associated with glucose-lowering drugs in patients with type 2 diabetes: a meta-analysis. JAMA 316:313–324CrossRefPubMedGoogle Scholar
- 18.Cappelli C, Rotondi M, Pirola I, Agosti B, Gandossi E, Valentini U, De Martino E, Cimino A, Chiovato L, Agabiti-Rosei E, Castellano M (2009) TSH-lowering effect of metformin in type 2 diabetic patients: differences between euthyroid, untreated hypothyroid, and euthyroid on L-T4 therapy patients. Diabetes Care 32:1589–1590CrossRefPubMedPubMedCentralGoogle Scholar
- 21.Balsamo C, Zucchini S, Maltoni G, Rollo A, Martini AL, Mazzanti L, Pession A, Cassio A (2015) Relationships between thyroid function and autoimmunity with metabolic derangement at the onset of type 1 diabetes: a cross-sectional and longitudinal study. J Endocrinol Invest 38:701–707CrossRefPubMedGoogle Scholar
- 23.Hill NR, Oliver NS, Choudhary P, Levy JC, Hindmarsh P, Matthews DR (2011) Normal reference range for mean tissue glucose and glycemic variability derived from continuous glucose monitoring for subjects without diabetes in different ethnic groups. Diabetes Technol Ther 13:921–928CrossRefPubMedPubMedCentralGoogle Scholar
- 26.Maratou E, Hadjidakis DJ, Kollias A, Tsegka K, Peppa M, Alevizaki M, Mitrou P, Lambadiari V, Boutati E, Nikzas D, Tountas N, Economopoulos T, Raptis SA, Dimitriadis G (2009) Studies of insulin resistance in patients with clinical and subclinical hypothyroidism. Eur J Endocrinol 160:785–790CrossRefPubMedGoogle Scholar