K Obuobie, J Smith, R John, JS Davies and JH Lazarus
OBJECTIVE: To assess central arterial stiffness in thyrotoxicosis using the technique of pulse wave analysis. DESIGN: Case control study designed to determine the effect of thyrotoxicosis on central arterial stiffness and at 6 months after radioiodine treatment. PATIENTS: Twenty (18 women and 2 men) thyrotoxic patients and 20 age- and sex-matched controls were studied at baseline. Thyrotoxic patients were re-studied at 6 months following treatment of thyrotoxicosis with 555 MBq (131)I with no additional therapy for the six-month period. MEASUREMENTS: Using the sphygmocor apparatus, peripheral pressure waveforms were recorded non-invasively from the radial artery and central pressure waveforms were generated from these. Indices of arterial stiffness, central augmentation index (AI), augmentation of central arterial pressure (AG) and central blood pressures were derived. AI corrected for heart rate (AIc) was calculated. RESULTS: Thyrotoxic patients recorded a significantly lower AI (means+/-s.e.m.) compared with controls (15.0+/-2.1 vs 28.0+/-2.1%; P<0.0005) even when corrected for differences in heart rate AIc (20.0+/-2.1 vs 28.0+/-2.1%; P<0.005) as well as AG (6.0+/-0.8 vs 10.0+/-1.1 mmHg; P<0.002) but higher pulse pressure (58.0+/-3.5 vs 47.0+/-2.0 mmHg; P<0.02). At 6 months following treatment, a significant rise in AIc (27.0+/-1.8 vs 20.0+/-2.1%; P<0.005) and AG (11.0+/-1.0 vs 6.0+/-0.8 mmHg; P<0.005) was noted. Lipid profiles were comparable between the groups. CONCLUSIONS: These data suggested that subjects with untreated thyrotoxicosis have a decreased augmentation of central arterial pressure or lowered central arterial stiffness that would not appear to contribute to any excess cardiovascular risk in that condition.
LD Premawardhana, AB Parkes, PP Smyth, CN Wijeyaratne, A Jayasinghe, DG de Silva and JH Lazarus
OBJECTIVE: Iodine deficiency was the likely cause of a high prevalence of goitre previously in Sri Lankan schoolchildren. Salt iodination was made compulsory in 1993 but there has been no recent study, using modern techniques, of its benefits or harmful effects. METHODS: Three hundred and sixty-seven schoolgirls between the ages of 11 and 16 years had ultrasound thyroid volume, free thyroxine (T4), free tri-iodothyronine (T3), thyrotrophin (TSH), anti-thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) antibodies, and urine iodine concentrations measured. RESULTS: Median ultrasound thyroid volume ranged from 4.8 ml (11-year-old girls) to 8.6 ml (16-year-old girls) with an age-related increase. Median urine iodine concentrations ranged from 105 to 152 microg/l. Free T4 and free T3 were normal in all, but TSH was elevated in four subjects (5. 53-41.29 mU/l). However, the prevalence of TgAb was markedly raised, ranging between 14.3% (11-year-old girls) and 69.7% (16-year-old girls) (P<0.03). In contrast, the prevalence of TPOAb was 10% or less in all age groups. CONCLUSIONS: Normal median thyroid volumes, iodine concentrations and thyroid function would indicate that iodine deficiency is not a major problem in this group. The high prevalence of TgAb, hitherto unreported, most likely reflects excessive iodination of Tg resulting in increased immunogenicity. There is an urgent need to continuously monitor the adequacy and risks of iodination in this population.
G Mazziotti, LD Premawardhana, AB Parkes, H Adams, PP Smyth, DF Smith, WN Kaluarachi, CN Wijeyaratne, A Jayasinghe, DG de Silva and JH Lazarus
OBJECTIVE: To study the evolution of thyroid autoimmunity, in relation to the change in goitre prevalence, during 3 Years of iodine prophylaxis in Sri Lanka. METHODS: Two groups of Sri Lankan schoolgirls between the ages of 10.8 and 17.5 Years were studied in 1998 (401 girls) and 2001 (282 girls). A prospective study was performed in 42 schoolgirls who were thyroid autoantibody (Ab)-positive (+ve) in 1998. Anthropometric measures, urinary iodine excretion (UIE), thyroid Volume, free thyroxine, free tri-iodothyronine, TSH, and thyroglobulin (Tg) and thyroid peroxidase (TPO) Ab were evaluated in all 683 girls. RESULTS: Goitre prevalence was significantly lower in 2001 compared with 1998 related to age (2.9% compared with 20.2%) and body surface area (11.6% compared with 40.8%), although UIE was unchanged. Prevalence of thyroid Ab in 2001 was also lower (23.4% compared with 49.9%); among those with the Ab, 34.8% had TgAb alone and 46.9% had a combination of TgAb+TPOAb, compared with 82.0% TgAb alone in 1998. In 2001, subclinical hypothyroidism was more frequent in Ab+ve (6.3%) than Ab-negative girls (1.0%). A cohort of 42 Ab+ve schoolgirls in 1998 (34 with TgAb alone, eight with TgAb+TPOAb) were evaluated again in 2001. Only 10 of them (23.8%) remained Ab+ve (mostly TPOAb+/-TgAb) in 2001. CONCLUSIONS: This study demonstrates that: (1) in 2001, goitre prevalence and thyroid autoimmunity rates were significantly lower than in 1998; (2) the pattern of thyroid Ab was different in the two surveys; (3) in 2001 alone, the occurrence of hypothyroidism was correlated with the presence of thyroid autoimmunity. These results indicate an evolution of thyroid autoimmune markers during the course of iodine prophylaxis, which has not been described before.
V Estienne, C Duthoit, VD Costanzo, PJ Lejeune, M Rotondi, S Kornfeld, R Finke, JH Lazarus, U Feldt-Rasmussen, WG Franke, P Smyth, M D'Herbomez, B Conte-Devolx, L Persani, C Carella, Jourdain JR, M Izembart, ME Toubert, A Pinchera, A Weetman, R Sapin, P Carayon and J Ruf
OBJECTIVE: TGPO autoantibodies (aAbs) that bind simultaneously to thyroglobulin (Tg) and thyroperoxidase (TPO) are present in the serum of patients with autoimmune thyroid diseases (AITD) and have been found to differ from monospecific Tg and TPO aAbs. To obtain further insights on the prevalence defined as the rate of occurrence and significance of TGPO aAbs in a large population, we carried out a collaborative study involving 15 European teams. METHODS: Serum samples from 3122 patients with various thyroid and non-thyroid diseases and normal subjects were assayed using a novel TGPO aAb detection kit. This test was designed so that TGPO aAbs are trapped between the Tg-coated solid phase and the soluble TPO labeled with a radioiodinated monoclonal antibody. RESULTS: Only three out of the 220 normal subjects (prevalence of 1.4%) were found to have positive TGPO aAb levels, which were mainly observed in the patients with AITD: the group of patients suffering from Hashimoto's thyroiditis had a TGPO aAb prevalence of 40.5% (n=437 patients), those with Graves' disease, a prevalence of 34.6% (n=645) and those with post-partum thyroiditis, 16.0% (n=243). Among the non-AITD patients with positive TGPO aAb levels, the TGPO aAb prevalence ranged from 20.7% among those with thyroid cancer (n=246) to 0% among those with toxic thyroid nodules (n=47). Among the patients with non-thyroid diseases, the TGPO aAb prevalence ranged from 9.8% in the case of Biermer's pernicious anemia (n=78) to 0% in that of premature ovarian failure (n=44). It is worth noting that the groups showing the highest TGPO aAb prevalence also contained the patients with the highest TGPO aAb titers. Statistical comparisons between the TGPO aAb prevalences in the various groups showed that TGPO aAb could be used as a parameter to distinguish between the groups of Hashimoto's and Graves' patients and between the women with post-partum thyroiditis and the post-partum women with only Tg and/or TPO aAb established during early pregnancy. Unexpectedly, the correlations between TGPO aAbs and Tg and TPO aAbs were found to depend mainly on the assay kit used. CONCLUSION: High TGPO aAb titers are consistently associated with AITD but the reverse was not found to be true. TGPO aAbs are a potentially useful tool, however, for establishing Hashimoto's diagnosis, and would be worth testing in this respect with a view to using them for routine AITD investigations.
MF Prummel, A Bakker, WM Wiersinga, L Baldeschi, MP Mourits, P Kendall-Taylor, P Perros, C Neoh, AJ Dickinson, JH Lazarus, CM Lane, AE Heufelder, GJ Kahaly, S Pitz, J Orgiazzi, A Hullo, A Pinchera, C Marcocci, MS Sartini, R Rocchi, M Nardi, GE Krassas and A Halkias
To improve management of patients with Graves' orbitopathy, a multi-center collaborative approach is necessary in order to have large enough sample sizes for meaningful randomized clinical trials. This is hampered by a lack of consensus on how to investigate the eye condition. The European Group on Graves' Orbitopathy aims to overcome this and has designed a preliminary case record form (CRF) to assess Graves' orbitopathy patients. This form was used in this first multi-center study. AIM: To investigate patient characteristics and treatment strategies in 152 new consecutively referred patients with thyroid eye disease seen in nine large European referral centers. METHODS: Newly referred patients with Graves' orbitopathy were included who were seen between September and December 2000. Demographic data and a complete ophthalmological assessment were recorded. RESULTS: One-hundred and fifty-two patients (77% females) were included. Diabetes was present in 9%, and glaucoma or cataract in 14% of patients. Forty percent were current smokers, 9% also had dermopathy, and only 33% reported a positive family history of thyroid disease. Mild eye disease was seen in 40%, moderately severe eye disease was seen in 33% and severe eye disease was seen in 28% of patients. Soft tissue involvement was the most frequent abnormality (seen in 75%), proptosis > or =21 mm was found in 63%, eye motility dysfunction in 49%, keratopathy in 16% and optic nerve involvement was found in 21% of patients. According to the clinical impression, 60% had active eye disease. Immunosuppressive treatment was planned more frequently in active patients (57/86; 66%) than in inactive patients (5/57, 9%; Chi-square 46.16; P<0.02). There were no important differences among the eight centers regarding the severity and the activity of their patients. CONCLUSIONS: In view of the large number of patients recruited in only 4 months, multi-center studies in the eight EUGOGO centers appear to be feasible.