Risks of suboptimal and excessive thyroid hormone replacement across ages.

BACKGROUND: Hypothyroidism is prevalent at all ages and represents a non-communicable disease with preventable consequences. METHOD: Narrative review. REVIEW: In children and adolescents, the most devastating consequences of undertreatment with levothyroxine (LT4) are poor growth and development. Delayed treatment in congenital hypothyroidism can lead to permanent brain damage. In young to middle-aged adults, symptoms are often overlooked, and treatment delayed by many years. The resulting consequences are also at this age group compromised brain and physical function but less severe and partly reversible with treatment. The under-treated condition often results in a higher risk of, e.g., increased cardiovascular disease burden, obesity, hypertension, poor physical capacity, and poor quality of life. Excessive replacement is at all adult age groups associated with increased risk of cardiac death, osteoporosis, loss of muscle function, psychological instability and poor quality of life. In young fertile women, the consequences of undertreatment with LT4 are subnormal fertility, recurrent pregnancy loss, compromised fetal growth, and neurocognitive development. On the other hand, excessive LT4 treatment has been related to gestational hypertension, preeclampsia and preterm birth. In the elderly, care must be given to avoid confusing a slightly high age-related serum TSH with requirement for LT4 treatment in a truly hypothyroid patient. Excessive LT4 treatment in patients of high age is associated with an increased mortality. CONCLUSION: Suboptimal and excessive LT4 replacement of the preventable non-communicable disease hypothyroidism requires more focus from the healthcare system and from the global political systems to prevent the personally devastating and socioeconomically challenging consequences.

No causal relationship between Yersinia enterocolitica infection and autoimmune thyroid disease: evidence from a prospective study.

The objective of this study was to evaluate prospectively the relationship between Yersinia enterocolitica (YE) infection and the development of overt autoimmune hypo- or hyperthyroidism (study A) and the de novo occurrence of thyroid antibodies (study B). This was a prospective cohort study of 790 euthyroid women who were first- or second-degree relatives of autoimmune thyroid disease (AITD) patients. Follow-up was 5 years, with annual assessments. Study A was a nested case-control study in which YE serological status was measured between cases {subjects who developed overt hypothyroidism [thyroid stimulating hormone (TSH) > 5·7 mU/l and free T4 (FT4) < 9·3 pmol/l] or overt hyperthyroidism (TSH < 0·4 mU/l and FT4 > 20·1 pmol/l)} and matched controls. For study B, 388 euthyroid women without thyroid antibodies at baseline were enrolled. The YE serological status was compared between subjects who developed thyroid peroxidase (TPO)-antibodies and/or thyroglobulin (Tg)-antibodies at 4-year follow-up and those who remained negative. For study A, the proportion of subjects positive for Yersinia enterocolitica outer membrane protein (YOP) immunoglobulin (Ig)G or YOP IgA did not differ between cases and controls at baseline. One year before the development of overt hypo- or hyperthyroidism, the proportion of subjects with YOP IgG was not different between cases and controls, but YOP IgA were less prevalent in cases. For study B, de novo occurrence of TPO (or TPO-antibodies and/or Tg-antibodies) did not differ between subjects in whom YOP IgG were positive or negative at baseline. Neither persistence nor emergence of YOP IgG at 4-year follow-up was associated with the occurrence of TPO-antibodies or Tg-antibodies. Similar results were observed with respect to YOP IgA. YE infection does not contribute to an increased risk of thyroid autoimmunity.

The aldosterone to renin ratio in the evaluation of patients with incidentally detected adrenal masses.

Incidentally discovered adrenal masses are diagnosed with increasing frequency, especially among patients with hypertension. Thus, a reliable screening test for primary hyperaldosteronism (PA) is essential to avoid unnecessary diagnostic procedures to this population. The aim of the present study is the evaluation of aldosterone to renin ratio (ARR), using plasma renin concentration, in the diagnostic algorithm of patients with adrenal incidentaloma. A total of 123 individuals were studied: 17 patients with proven PA (age 55.5 +/- 1.4 years), 27 patients with nonfunctioning adrenal incidentaloma (age 60.3 +/- 1.8 years, 14 hypertensives and 13 normotensives) and 79 control subjects (age 58.7 +/- 1.4 years, 27 hypertensives and 52 normotensives). A receiver operating characteristic (ROC) analysis disclosed that an ARR > or =32 combines a sensitivity of 100% with a specificity of 96.2% for the diagnosis of PA. No difference in AlphaRR between hypertensive and normotensive individuals harbouring an adrenal incidentaloma and hypertensive and normotensive controls was found. Patients with adrenal incidentalomas with subtle glucocorticoid hypersecretion demonstrated similar ARR compared to patients with normal cortisol secretion. In conclusion, ARR is reliable for the exclusion of PA in patients with adrenal incidentalomas. Furthermore, subtle aldosterone hypersecretion, as indicated by increased ARR, in patients with adrenal incidentalomas is not associated with the presence of hypertension or subtle glucocorticoid hypersecretion.