Adv Gen Pract Med
Received: January 11, 2019; Accepted: February 1, 2019; Published: February 3, 2019;
Correspondence to: Salem Bouomrani, Department of Internal medicine, Military Hospital
of Gabes, Gabes 6000, Tunisia; Sfax Faculty of Medicine, University of Sfax, Sfax
3029, Tunisia; Email: salembouomrani@yahoo.fr
1 Department of Internal medicine. Military Hospital of Gabes. Gabes 6000. Tunisia;
2 Sfax Faculty of Medicine. University of Sfax. Sfax 3029. Tunisia;
3 Department of Psychiatry. Gabes Regional Hospital. Gabes 6000. Tunisia.
Citation: Bouomrani S, Guermazi M, Yahyaoui S, et al. Depression of the elderly revealing a primary hypothyroidism. Adv Gen Pract Med, 2019, 2(1): 1-4.
Copyright: © 2019 Salem Bouomrani, et al. This is an open access article distributed under the terms of the Creative Commons Attribution License which permits unrestricted use, dis- tribution, and reproduction in any medium, provided the original author and source are credited.
Introduction
Hypothyroidism is a very common endocrinopathy. The prevalence of overt/symptomatic forms of hypothyroidism varies from 0.2 to 5.3% depending on the series according to the definitions and retained threshold values of the thyroid hormones [1]. Subclinical/asymptomatic forms of hypothyroidism are by far the most common with prevalence exceeding 10% in most studies and populations [2]. Subclinical hypothyroidism is particularly common in elderly with prevalence of up to 20% in subjects over 60 years [3,4], and we estimate that 2.5% of subjects with subclinical hypothyroidism progress annually towards an overt form [5].
Despite their frequency and ease of diagnosis, these endocrinopathies remain underdiagnosed; a meta-analysis of studies in nine European countries estimated the prevalence of undiagnosed cases of hypothyroidism (both overt and subclinical) at 5% of the general population [6].
This difficulty is mainly due to the large clinical polymorphism of this disease with sometimes so-called "unusual" modes of revelation [1]: rheumatologic [7], digestive [8], neuromuscular [9], cardiac [2], and psychiatric [10] justifying the qualification of "great simulator" attributed to this endocrinopathy [11].
We report an original observation of primary hypothyroid in the elderly revealed
by an isolated depressive syndrome.
A 78-year-old patient, followed for essential hypertension, well-balanced with
calcium channel blockers and without degenerative complications, was referred by
her family doctor for depressive syndrome not improved by the specific treatment
prescribed and correctly taken for six months.
His symptomatology was insomnia, sadness of mood, asthenia, and loss of vital
impetus.
The basic biological tests (blood count, creatinine, serum calcium, erythrocyte
sedimentation rate, fasting blood glucose, transaminases, total cholesterol,
triglycerides, and ionogram) as well as the cerebral computed tomography
requested by his family doctor were without abnormalities.
No particular family or personal psychiatric history was revealed. Similarly, no
recent traumatic event or specific drug or toxic intake was reported.
The clinical examination in our department noted in particular a macroglossia
(Figure 1) with bilateral dental impressions
(Figure 2) and dry and cracked skin (Figure 3, 4 and 5). The biological assessment showed hypothyroidism with Thyroid Stimulating
Hormone (TSH) at 28 $\mu{}$mol/l and a total thyroxine at 2 pmol/l. Thyroid
ultrasound showed atrophy of the thyroid gland. The thyroid autoimmunity
(anti-thyroglobulin and anti-thyroperoxidase antibodies) was negative. The rest
of the biological tests were in the normal range. The diagnosis of overt primary
hypothyroidism by Riedel's thyroiditis was retained and the patient was put on
levothyroxine in progressive doses until normalization of TSH.
The evolution on the psychiatric level was also favorable with disappearance of
the signs of the depression and anti-depressive treatment was discontinued. No
recurrence of depressive symptoms has been noted for six years.
Hypothyroidism is a common condition in the elderly and often under-diagnosed
especially in its asymptomatic forms (subclinical hypothyroidism) [12]. The
diagnosis of depression associated with hypothyroidism is even more difficult,
even in the overt forms of this endocrinopathy because these two conditions share
several clinical features [13,14], and often the clinical signs of hypothyroidism
can lend confusion with those of the depressive syndrome [15].
The psychiatric manifestations are seen in 5 to 15% of the primary
hypothyroidism [16] and are also frequent during subclinical hypothyroidism [17],
and particularly in the elderly [13,17]. Psychiatric manifestations associated
with hypothyroidism include cognitive impairment, affective disorders, dementia,
encephalitis, and psychosis [13-19}. These manifestations may be severe [18,19],
and may exceptionally reveal the disease [10,18].
Depression remains rare, complicating only 4% of overt hypothyroidism [20] and
is often characterized by its severity and its resistance to antidepressant
therapy [21,22]. Indeed, the multicenter European study of resistant depression
(GSRD Study) performed on 1410 patients, showed that 13% of subjects with a
major depressive syndrome had underlying hypothyroidism [21].
This depression appears to be more common in elderly subjects, particularly
women, and it has been shown that hypothyroid women are significantly predisposed
to the development of depressive syndrome regardless of their basic demographic
and socio-economic characteristics [20].
The particular frequency of depression during hypothyroidism suggests common
mechanisms to the point that several authors present the hypothesis of "brain
hypothyroidism" to explain the pathogenesis of depression during this
endocrinopathy [13]. This theory is based on the effects of deprivation in
thyroid hormones on brain tissue, and on the direct effects of thyroid pathology,
especially autoimmune thyroiditis [17]. Indeed, Siegmann EM meta-analysis in 2018
demonstrated a significant association between hypothyroidism by autoimmune
thyroiditis and depression with an odds ratio of 3.56 [22]. The high levels of
pro-inflammatory cytokines during these thyroiditis, particularly interleukin-6
(IL-6), and tumor necrosis factor-alpha (TNF-$\alpha{}$), are involved in the
pathogenesis of associated depressive syndromes [23].
In overt forms, the simple hormone replacement therapy of hypothyroidism
significantly improves and even eliminates mood disorders, including depression,
in these subjects [15,17-20]. In the subclinical forms of hypothyroidism, and
even in the absence of consensus, the presence of neuropsychiatric manifestations
is an indication for hormone replacement therapy [24].
In this context, the interesting study of Talaei A et al allowed to define a
"TSH cut off point" associated with depression in patients treated for
hypothyroidism. It seems that depression is significantly associated with a cut
off of 2.5 $\mu{}$mol/l and severe depression with a TSH cut off point of 4
$\mu{}$mol/l [13]. Thus the optimal TSH recommend in hypothyroid treated subjects
to avoid the development of depressive syndrome is 2.5 $\mu{}$mol/l [13].
Hypothyroidism revealed by psychiatric manifestations is not always easy to
diagnose in the elderly. This depression does not seem to depend on the value of
TSH and can be seen in both overt and subclinical hypothyroidism. Thus, it is
advisable to ask a TSH for any depressive syndrome in the elderly to diagnose an
underlying hypothyroidism early, and improve the prognosis by improving the
quality of life and avoiding cognitive decline.
The authors declared that they have no conflicts of interest to this work.
Case report
Discussion
Conclusion
Conflicts of interest