| 1. |
- Hansson, P, et al.
(författare)
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Experimental hyperthyroidism in man: effects on plasma lipoproteins, lipoprotein lipase and hepatic lipase
- 1983
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Ingår i: Hormone and Metabolic Research. - 1439-4286. ; 15:9, s. 449-452
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the effects of triiodothyronine administration (20-40 micrograms three times daily over one week) in six healthy young men, on the activities of lipoprotein lipase and hepatic lipase and on plasma lipoprotein concentrations. Hepatic lipase activity in post-heparin plasma rose by 46 +/- 25% (p less than 0.025), whereas the activity of lipoprotein lipase did not change significantly. Plasma cholesterol concentrations decreased by about 20% (p less than 0.025), whereas there was no change in plasma triglyceride levels. The fall in plasma cholesterol could be accounted for by a reduction of HDL cholesterol (-11%, p less than 0.025) as well as LDL cholesterol (-27%, p less than 0.025). The data emphasize the role of hepatic lipase in the lipoprotein alterations associated with thyroid dysfunction.
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| 2. |
- Valdemarsson, Stig, et al.
(författare)
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Relations between thyroid function, hepatic and lipoprotein lipase activities, and plasma lipoprotein concentrations
- 1983
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Ingår i: Acta Endocrinologica. - 0001-5598. ; 104:1, s. 50-56
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein concentrations and activities of lipoprotein lipase (LPL) and hepatic lipase (HL) were measured in 70 subjects with thyroid function ranging from overt hypothyroidism over subclinical hypothyroidism and euthyroidism to hyperthyroidism. In parallel with serum T3 (S-T3) concentrations increasing from low in hypothyroidism to high in hyperthyroidism there were gradually higher HL activities over the full spectrum of thyroid function, accompanied by decreasing levels of total and low density lipoprotein (LDL) cholesterol. High density lipoprotein (HDL) cholesterol was lower (P less than 0.05) in hyperthyroidism than in euthyroidism but not significantly changed in the hypothyroid groups. HL was correlated to S-T3 (r = 0.77, P less than 0.001), LDL cholesterol to log S-T3 (r = -0.76, P less than 0.001), and LDL cholesterol to log HL (r = -0.55, P less than 0.001). The activity of LPL was decreased (P less than 0.001) in overt hypothyroidism compared to euthyroidism but, in contrast to HL, the activity of LPL was not increased in hyperthyroidism. The plasma triglyceride (P-TG) concentration was elevated (P less than 0.01) in overt hypothyroidism but not significantly changed in subclinical hypothyroidism or in hyperthyroidism. The LPL activity was correlated to log S-T3 (r = 0.45, P less than 0.001), P-TG to log S-T3 (r = -0.37, P less than 0.01) and P-TG to log LPL activity (r = -0.71, P less than 0.001). Our results demonstrate that thyroid hormones influence HL and LPL activities in different ways, suggesting different mechanisms of action. Changes in HL activity seem to be an important mechanism for the disturbance of cholesterol metabolism in thyroid dysfunction while the thyroid hormone influence on LPL seems to be of importance mainly for the disturbance in triglyceride metabolism.
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| 3. |
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| 4. |
- Agardh, Carl-David, et al.
(författare)
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Plasma high density lipoproteins and lipolytic enzyme activities in diabetic patients
- 1983
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Ingår i: Acta Medica Scandinavica. - 0001-6101. ; 213:2, s. 123-128
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Tidskriftsartikel (refereegranskat)abstract
- Eighty diabetic patients, consecutively selected from an out-patient clinic, were studied with regard to plasma lipoprotein levels, especially HDL. Patients treated with sulphonylureas had 24% lower HDL cholesterol concentrations (p less than 0.01) but only about 7% lower apo AI levels (n.s.) than those on insulin treatment. This difference could at least partly be explained by differences in age and type of diabetes. There was no relationship between the degree of diabetic control, as measured by fasting blood glucose levels, and HDL levels. In two subgroups of insulin-treated diabetics, selected to represent extremely low and high HDL levels (range 0.5-0.8 and 1.8-2.0 mmol/l, respectively) but matched with regard to age, duration of diabetes, insulin dosage and diabetic control, the activities of lipoprotein lipase and hepatic lipase in postheparin plasma were also recorded. The high HDL group had significantly higher lipoprotein lipase activities (p less than 0.01) and significantly lower hepatic lipase activities (p less than 0.05) than the low HDL group, supporting the hypothetical roles of these enzymes in HDL metabolism, and offering a tentative mechanism behind the large variability of HDL levels in diabetics.
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