Lipoprotein(a) Concentration in Subclinical Hypothyroidism Before and After Levo-Thyroxine Therapy.

Leptin is the protein product of the ob gene, secreted by adipocytes. It has been suggested that it may play an important role in regulating appetite and energy expenditure. The aim of this study was to evaluate a possible interaction of thyroid hormones with the leptin system. We studied 114 adult patients (65 females and 49 males): 36 were affected with primary hypothyroidism (PH), 38 with central hypothyroidism (CH) and 40 with thyrotoxicosis (TT). Patients with CH were studied both before and after 6 months of L-thyroxine replacement therapy. Body mass index (BMI; kg/m2), thyroid function and fasting serum leptin were assessed in all patients. Since BMI has been proved to be the major influencing variable of circulating leptin levels, data were expressed as standard deviation score (SDS) calculated from 393 male and 561 female controls matched for age and BMI. No difference in SDS was recorded between males and females whatever the levels of circulating thyroid hormones. In males, no significant difference was recorded among the SDSs of PH (-0.36 +/- 1.2), TT (-0.35 +/- 1.2) and CH (0.01 +/- 1.4) patients. Females with PH had an SDSs significantly lower than TT females (-0.77 +/- 1.0 vs -0.06 +/- 1.2; P < 0.02), while no significant differences between CH (-0.34 +/- 0.7) and TT females or between CH and PH females were observed. SDS in CH patients after 6 months of L-thyroxine therapy significantly varied only in females (0.25 +/- 1.4). In conclusion, circulating thyroid hormones do not appear to play any relevant role in leptin synthesis and secretion. However, as females with either overt hypo- or hyper-thyroidism or central hypothyroidism after L-thyroxine therapy show differences in their SDSs, a subtle interaction between sex steroids and thyroid status in modulating leptin secretion, at least in women, may occur.

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The effect of levothyroxine in comparison with placebo on serum osteocalcin levels in patients with subclinical hypothyroidism

Current Drug Safety ◽

10.2174/1574886316666210525102230 ◽

2021 ◽

Vol 16 ◽

Author(s):

Reihaneh Rezaee ◽

Masoud Mohebbi ◽

Mozhgan Afkhamizadeh ◽

Mohammad Ali Yaghoubi ◽

Mona Najaf Najafi ◽

...

Keyword(s):

Thyroid Hormones ◽

Subclinical Hypothyroidism ◽

Intervention Group ◽

Serum Levels ◽

Overt Hypothyroidism ◽

Serum Osteocalcin ◽

Significant Difference ◽

Before And After ◽

Metabolic Conditions ◽

And Control

Background and Objective: Subclinical hypothyroidism can potentially develop to overt hypothyroidism. Thyroid hormones have substantial roles in metabolism and glucose homeostasis and thus are closely related to determinant factors of metabolic syndromes, such as obesity and insulin resistance. Osteocalcin is considered a predictor of metabolic conditions in thyroid diseases. This study aimed to investigate the effect of levothyroxine vs. placebo on serum osteocalcin levels in patients with subclinical hypothyroidism. Methods: This randomized clinical trial was performed on 30 patients with subclinical hypothyroidism who were referred to the endocrine clinics of Ghaem and Imam Reza hospitals in Mashhad, Iran. After giving informed consent, patients were randomly divided into intervention (50 µg/day levothyroxine for 2 months) and control (placebo) groups. Serum levels of osteocalcin, thyroid hormones, lipid profile, insulin, and fasting glucose, as well as other clinical and anthropometric data, were measured at baseline and at the end of the study. SPSS was used to analyze the data and P<0.05 was considered significant. Results: Mean age in the intervention and control groups was 35.07 ± 9.94 and 31.30 ± 4.30, respectively (P=0.20). There was no significant difference between osteocalcin levels before and after the intervention in either of the groups (P=0.54). TSH level was significantly decreased in the levothyroxine group after the intervention (P<0.01). T4 level was significantly increased in the intervention group (P=0.02). Conclusion: Levothyroxine had no significant effect on increasing the levels of serum osteocalcin in patients with subclinical hypothyroidism. We have registered the trial in the Iranian registry of clinical trials (IRCT) with the registration code IRCT20171129037677N1.

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Lipoprotein(a) and postmenopausal oestrogen

Acta Endocrinologica ◽

10.1530/acta.0.1290225 ◽

1993 ◽

Vol 129 (3) ◽

pp. 225-228 ◽

Cited By ~ 15

Author(s):

Elizabeth Farish ◽

Hilary A Rolton ◽

Judith F Barnes ◽

Colin D Fletcher ◽

David J Walsh ◽

...

Keyword(s):

Marked Effect ◽

Density Lipoprotein ◽

Epidemiological Studies ◽

Oestrogen Therapy ◽

Bilateral Oophorectomy ◽

Short Term ◽

Serum Samples ◽

Lipoprotein A ◽

Before And After ◽

Unopposed Oestrogen

Epidemiological studies have shown that postmenopausal oestrogen therapy substantially reduces the risk of cardiovascular and cerebrovascular disease and this is partly mediated by oestrogen-associated changes in lipoproteins, particularly high-density lipoprotein. In this study, we investigated whether changes in lipoprotein(a) might help to account for the reduction in coronary heart disease and stroke associated with postmenopausal oestrogen therapy. The study group consisted of 18 women who had hysterectomy and bilateral oophorectomy at least 2 months prior to recruitment and had received no previous hormonal therapy. Serum samples were collected for measurement of lipoprotein(a) before and after 4 months of treatment with oestradiol valerate (2 mg/day). Lipoprotein(a) levels ranged from 35 to 720 mg/l (median 180 mg/l) before treatment and from 55 to 780 mg/l (median 1 30 mg/l) after oestradiol treatment and showed no consistent pattern of change. It would appear, therefore, that treatment with unopposed oestrogen in relatively low doses does not have a marked effect on lipoprotein(a), at least in the short term.

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D-thyroxine reduces lipoprotein(a) serum concentration in dialysis patients.

Journal of the American Society of Nephrology ◽

10.1681/asn.v9190 ◽

1998 ◽

Vol 9 (1) ◽

pp. 90-96

Author(s):

C Bommer ◽

E Werle ◽

I Walter-Sack ◽

C Keller ◽

F Gehlen ◽

...

Keyword(s):

Serum Concentration ◽

Ldl Cholesterol ◽

Clinical Symptoms ◽

Hormone Secretion ◽

Elevated Serum ◽

Serum Levels ◽

Controlled Study ◽

Dialysis Patients ◽

Lipoprotein A ◽

Thyroxine Therapy

Uremia raises lipoprotein(a) (Lp(a)) serum concentration and the risk of arteriosclerosis in dialysis patients. The treatment of high Lp(a) levels is not satisfactory today. The decrease of Lp(a) in hypothyroid patients on L-T4 therapy raised the question of whether dextro-thyroxine (D-thyroxine) reduces not only serum cholesterol, but also Lp(a) serum concentration. In a single-blind placebo-controlled study, the influence of D-thyroxine therapy on Lp(a) serum concentration was evaluated in 30 hemodialysis patients with elevated Lp(a) serum levels. Lp(a) was quantified in parallel by two methods, i.e., rocket immunoelectrophoresis and nephelometry, and apo(a) isoforms were determined by a sensitive immunoblotting technique. Regardless of the apo(a) isoforms, 6 mg/d D-thyroxine reduced elevated Lp(a) levels significantly by 27 +/- 13% in 20 dialysis patients (P < 0.001) compared with 10 control subjects (-9.9 +/- 8.4%). In parallel, D-thyroxine therapy significantly lowered total cholesterol (P < 0.001), LDL cholesterol (P < 0.001), and LDL cholesterol/HDL cholesterol ratio (P < 0.01); raised T4 and T3 serum levels; and suppressed thyroid-stimulating hormone secretion without causing clinical symptoms of hyperthyroidism in any of the patients. D-Thyroxine reduces elevated serum Lp(a) concentration in dialysis patients. The effect in nondialysis patients can be expected but remains to be proven.

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Coagulation Activation in Extracorporeal Hemodialysis

The International Journal of Artificial Organs ◽

10.1177/039139889702000307 ◽

1997 ◽

Vol 20 (3) ◽

pp. 163-165 ◽

Cited By ~ 6

Author(s):

M. Camici ◽

L. Evangelisti ◽

P. Balestri ◽

L. Cioni ◽

P. Fundi ◽

...

Keyword(s):

Protein C ◽

Serum Lipoprotein ◽

Factor Vii ◽

Maintenance Hemodialysis ◽

Factor X ◽

Lipoprotein A ◽

Activity Factor ◽

Before And After ◽

Protein C Activity

The Authors evaluated the behavior of protein C activity, factor X and factor VII coagulant activity and serum lipoprotein(a) before and after dialytic treatment in patients on maintenance hemodialysis. They observed depressed protein C activity that significantly (p<0.005) increased and became normal immediately after hemodialysis while factor X and factor VII increased (p<0.01; p<0.05) despite heparinization together with amount of serum lipoprotein(a). In vitro incubation (30 'at 37°C) of uremic and healthy blood showed a decrease in serum lipoprotein(a) concentration. After heparin addition (final concentration 0.5 U/ml) lipoprotein(a) increased in the uremic blood only. The clinical and physiopathological implications of these results are discussed.

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