Validity of serum CK activity in the diagnosis of thyroid dysfunction

This study assessed the pattern of changes in serum creatine kinase [CK] activity in [100] patients with a variety of clinical manifestations of either increased or decreased thyroid function and evaluated the validity of such changes in the diagnosis of both conditions They were biochemically assessed for thyroid function and compared with a control group of 67 apparently healthy subjects According to thyroid function tests, the subjects were classified into 3 groups Group 1 Hypothyroid patients [n=50], which was divided into 2 subgroups Group A[Overt hypothyroidism] It included 43 patients with TT4 60 nmol/l. The second group [Group 2] included 50 hyperthyroid patients, while [Group 3] was composed of 67 euthyroid subjects. Serum CK activity was noticeably elevated in hypothyroid patients compared to both normal and hyperthyroid subjects [mean +SD was 204.10 + 97.72 Vs 79.97+ 26.35 and 79.36 + 26.88 u/L respectively]. There was no significant difference in the mean serum CK activity between group A and B [Z =87, P>0.05] A significant positive correlation was revealed between serum TSH and CK in hypothyroid patients [Group I] where [r=0.35, P<0.01], while there was no such significant association in either group A or B [p>O.O5],and thus did the hyperthyroid patients [r= -0.22, P>0.05]. For patients in group1, the sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV], accuracy rate, positive likelihood ratio [PLR] and negative likelihood ratio [NLR] of elevated serum CK activity as a diagnostic test were 74%, 95.5%, 92.5%, 87%, 86%, 16.40, 0.27 respectively. However, they were 0%, 95.5%, 0%, 56%, 5.4%, 0 and 0.96 respectively for the diagnosis of hyperthyroidism. In conclusion high serum CK activity is a fairly sensitive and highly specific test for the diagnosis of hypothyroidism with a high PPV value mainly for overt [uncompensated] cases. This study indicates that the determination of CK might be a useful screening tool for hypothyroidism

Effect of thyroidectomy on fast and slow muscle fibres of rat gastrocnemius muscle.

A combined histochemical, biochemical and electrophoretic study with respect to the enzymes succnic dehydrogenase(SDH), myofibrillar adenosine triphosphatase (m-ATPase), lactate dehydrogenase (LDH) isozymes and myosin light chains was carried out to investigate the response of rat gastrocnemius muscle (medial head). Twelve weeks after thyroidectomy, the results indicated a shift from fast to slow type pattern of LDH isozymes, fibre type transformation from Type II to Type I and a decrease in SDH and m-ATPase activity. The results suggest, possible thyroidal involvement in determining the phenotypic properties of skeletal muscle.

Dorsolateral prostatic phosphomonoesterases and adenosine triphosphatases in hypo- and hyperthyroid rats.

Specific activities of phosphomonoesterases (acid and alkaline phosphatases) and adenosine triphosphatases (Mg2+, Ca2+ and Na+/K+ dependent ATPases) of dorsolateral prostate were studied in albino rats, under altered thyroid hormone status. Thyroidectomy induced hypothyroidism and thyroxine administered hyperthyroidism (25 micrograms/100 g body wt/day for 60 days, im) showed no impact on the activity of acid phosphatase. Three fold decrease in the activity of alkaline phosphatase was observed in hyperthyroid group. Ca2+ and Mg2+ dependent ATPases were significantly decreased in hypo- and hyperthyroid status whereas Na+/K+ ATPase was decreased in hyperthyroidism and showed an opposite trend in hypothyroid group.

Specific activities of seminal vesicular phosphomonoesterases and Mg2+-,Ca2+- and Na+/K(+)-adenosine triphosphatases in hypo- and hyperthyroid albino rats.

Hypothyroidism (surgical thyroidectomy) inhibited the activities of acid phosphatase and Mg(2+)-ATPase in seminal vesicular tissue and fluid and that of Ca(2+)- and Na+/K(+)-ATPases in fluid alone, and T4 supplementation restored normalcy in all, except acid phosphatase. Hyperthyroidism (T4 25 micrograms/100g body weight/day for 60 days, im) enhanced the activities of alkaline phosphatase and ATPases in seminal vesicular tissue and fluid, and decreased acid phosphatase activity in tissue alone. Withdrawal of T4 treatment from hyperthyroid rats (after 30 days) augmented the activity of ATPases in tissue and impaired the same in fluid, while phosphomonoesterases remained at hyperthyroid level. The results suggest specific responses of various seminal vesicular phosphatases to altered thyroid hormone status. Modification in the specific threshold of androgen/estrogen action on different phosphatases in seminal vesicles appears to be the plausible mechanism underlying these changes in hypo- and hyperthyroid conditions.

Ventral prostatic phosphomonoesterases and adenosine triphosphatases in hypo- and hyperthyroid albino rats.

Specific activities of prostatic phosphomonoesterases (acid and alkaline phosphatases) and adenosine triphosphatases (Mg2+, Ca2+ and Na+/K+ dependent ATPases) were studied in albino rats, under altered thyroid hormone status. Thyroidectomy induced hypothyroidism decreased the specific activities of acid and alkaline phosphatases, Na+/K+ and Ca2+ dependent ATPases in ventral prostate. Hyperthyroidism (25 micrograms thyroxine/100g body weight/day for 60 days, im) enhanced the activities of acid phosphatase and Na+/K+ dependent ATPase, while Ca2+ dependent ATPase decreased. The altered thyroid status had no effect on the activity of ventral prostatic Mg2+ dependent ATPase. The data obtained in the present study showed differential and specific responses of various ventral prostatic phosphatases to the hypo or hyperthyroid status. The study also shows the necessity of an optimum level of thyroid hormones to maintain the normal activities of these enzymes and their secretory function in ventral prostate.

Alteraçöes da CPK e da isoenzima da CPK no hipotiroidismo primário antes e após o tratamento com hormônio tiroidiano / CPK and CPK isoenzyme changes in primary hypothyroidism before and after treatment with thyroid hormone

Este estudo foi realizado para analisar as alteraçöes da CPK e da isoenzima da CPK (CK-MB) no hipotiroidismo primário antes e após o tratamento com doses incrementais de L-T. Doze pacientes com hipotiroidismo primário foram estudados e as concentraçöes plasmáticas de CPK, CK-MB, TSH, T e T foram feitas antes e após (15 e 45 dias) de tratamento com L-T. O CPK basal foi significantemente elevado na maioria dos pacientes (9/12), quando comparado com controles normais (p < 0,5). Após o 15- dia de tratamento os valores foram ainda elevados (p < 0,05), declinando a níveis normais somente após o 45- dia de tratamento. Os níveis de CK-MB (fraçäo cardíaca) plasmático estavam dentro de oscilaçöes normais. Nós concluímos que: 1) pacientes com hipotiroidismo primário têm alteraçöes de CPK (83,3% tiveram aumento de CPK); 2) esta elevaçäo é provavelmente devida a um extravasamento dessa enzima do músculo esquelético; 3) houve normalizaçäo dos níveis de CPK durante o curso do tratamento com L-T

Alteraçöes enzimáticas no hipotirodismo primário: características bioquímicas antes e após a terapêutica com doses incrementais de L-tiroxina / Enzymatic changes in primary hypothyroidism before and after treatment with increased doses of L-thyroxine

O objetivo deste estudo foi analisar as alteraçöes enzimáticas no hipotiroidismo primário antes e após a terapêutica com tiroxina. Para tal, estudamos 12 pacientes com hipotiroidismo primário, nos quais medimos os valores séricos de CPK, CK-MB, DHL, isoenzimas de DHL, TGO, TSH, T4 e T3 antes do tratamento, 15 e 45 dias após a terapêutica com tiroxina. A CPK basal apresentava-se com valores elevados na maioria dos pacientes; (9/12) e significantemente aumentada em relaçäo aos controles normais (p < 0,05); após 15 dias de terapêutica os valores ainda permaneciam aumentados (p < 0,05) e no 45§ dia de terapêutica estavam dentro da normalidade em todos os pacientes;. A contribuiçäo de fraçäo cardíaca (CK-MB) foi sempre mínima e dentro dos valores normais. A DHL total basal apresentava-se com valores aumentados em 5 dos 12 pacientes e significantemente aumentada em relaçäo aos controles normais (p < 0,05); após 15 dias de terapêutica os valores ainda permaneciam elevados (p < 0,05) e no 45§ dia estavam dentro da normalidade em todos os pacientes; a avaliaçäo isoenzimática revelou elevaçäo da fraçäo 5. A TGO basal apresentava-se com valores aumentados na maioria dos pacientes; (7/12) e significantemente aumentada em relaçäo aos controles normais (p < 0,05); após 15 dias de terapêutica os valores ainda permaneciam elevados (p < 0,05) e no 45§ dia estavam dentro da normalidade em todos os pacientes;. O TSH basal apresentava-se com valores aumentados em todos os pacientes; e significantemente mais elevados comparativamente a controles normais (p < 0,05) mesmo após 15 e 45 dias de terapêutica (p < 0,05). Os dados obtidos demonstram: 1) pacientes com hipotiroidismo primário evidenciam anormalidades enzimáticas (83,3% possuem CPK elevada, 41,7% apresentam DHL elevada e 58,3% mostram TGO elevada); 2) a elevaçäo enzimática é provavelmente decorrente de alteraçöes musculares; 3) as alteraçöes enzimáticas retornam à normalidade com a terapêutica à base de tiroxina precocemente em relaçäo ao TSH