Hyperlipidaemia in patients with hypopituitarism

Biphasic dyslipidemia in a patient with painless thyroiditis

In this case study, we followed the thyroid function and serum lipid levels of a patient with painless thyroiditis. Serum lipid levels were decreased during the hyperthyroid phase and elevated during the hypothyroid phase. Both serum lipid levels and thyroid function returned to normative values following a course of thyroid replacement treatment.

Best practice in primary care pathology: review 3

This best practice review examines four series of common primary care questions in laboratory medicine: (i) "minor" blood platelet count and haemoglobin abnormalities; (ii) diagnosis and monitoring of anaemia caused by iron deficiency; (iii) secondary hyperlipidaemia and hypertriglyceridaemia; and (iv) glycated haemoglobin and microalbumin use in diabetes. The review is presented in question-answer format, referenced for each question series. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards, but form a guide to be set in the clinical context. Most of the recommendations are based on consensus rather than evidence. They will be updated periodically to take account of new information.

Hypercholesterolemia and obesity in adult patients with hypopituitarism: a report of a nation-wide survey in Japan

Dyslipidemia and obesity are common in adult patients with hypopituitarism. Possible contributions of age, sex and hormone deficiencies to hypercholesterolemia and obesity in adult hypopituitary patients were analyzed in 1, 272 Japanese cases based on a database of a national survey on adult hypopituitarism. In patients on routine hormone replacement therapy, 30.5% of male and 40.7% of female subjects were considered hypercholesterolemic. In univariate analysis, hypercholesterolemia was more prevalent in female, aged, untreated Gn-deficient and TSH-deficient groups. In multivariate analysis, sex of female, age older than 40 yr and TSH deficiency were the independent contributing factors to hypercholesterolemia. Obesity (body mass index (BMI) > or = 25 kg/m2) was more prevalent in male, TSH-deficient and ADH-deficient groups. Severe obesity (BMI > or = 30) was observed in high prevalence in the youngest group. These findings suggest that hypercholesterolemia and obesity were prevalent in different age and gender groups in Japanese adult patients with hypopituitarism. Insufficient replacement of thyroid hormone and possibly gonadotropin deficiency might contribute to hypercholesterolemia. In contrast, hypothalamic dysfunction as well as hormone deficiencies might play roles in obesity in these patients.

A screening method for abnormally high lipoprotein(a) concentrations by agarose lipoprotein electrophoresis

A routine electrophoretic method detecting plasma lipoprotein(a) (Lp(a)) is described. Plasma lipoproteins were electrophoresed using an agarose gel film containing cations which retard migration of beta-, prebeta- and alpha-bands. When present, the Lp(a)-band was detected between prebeta- and alpha-bands. This extra-band lipoprotein has been demonstrated to be Lp(a), by an immunofixation technique using anti-Lp(a) antibodies. This original procedure allows a distinct separation of Lp(a) from prebeta even after samples have been stored at 4 degrees C for several days, or in cases of hyperlipemic samples with increased prebeta lipoproteins. The reliability of this detection test has been tested in comparison with an Lp(a) electroimmunoassay. Both these techniques have been performed on 719 randomly selected subjects. With electrophoresis, the Lp(a)-positive subjects accounted for 34.2% of the subjects and although this method does not distinguish between different levels of positivity (depending on the sample), the presence of Lp(a)-band was always perceptible at concentrations that belong to the upper 15th percentile of values as determined by electroimmunodiffusion; inversely, all Lp(a)-positive plasma was measurable. In consequence, since it is reliable and relatively inexpensive, this detection test on modified agarose gel appears very useful for revealing the presence of abnormally high values of Lp(a) in populations.

Serum lipoprotein(a) levels differ in different phenotypes of primary hyperlipoproteinemia

Previous studies have indicated that serum lipoprotein(a) [Lp(a)] levels are mostly under genetic control. We have attempted to determine whether serum Lp(a) levels differ in different phenotypes of primary hyperlipoproteinemia (HL). A total of 129 subjects with HL (three with type I, 43 with familial hypercholesterolemia [FH], 17 with type IIa [non-FH], 11 with type IIb, six with type III [E2/2], 44 with type IV, and five with type V) and 18 normolipidemic controls were included in the study. Thirty-two FH subjects were being treated with hypolipidemic agents, but none of the other subjects were receiving any medication. Fasting blood samples were collected for determination of both serum lipid and Lp(a) levels. Lp(a) level was measured by enzyme-linked immunosorbent assay. The 18 controls had serum Lp(a) concentrations of 18.0 +/- 14.5 mg/dL (mean +/- SD), and four of them had high serum Lp(a) levels (> or = 25 mg/dL). Serum Lp(a) concentrations in FH subjects tended to be higher than in the controls (30.5 +/- 25.0 mg/dL), and the incidence of high Lp(a) levels in FH subjects was significantly higher than in the controls (51% v 22%, P < .01). There was no difference between serum Lp(a) levels of FH subjects depending on whether they were receiving medication. In contrast, most of the subjects with selective hypertriglyceridemia had very low serum Lp(a) levels (1.5 +/- 0.7, 8.1 +/- 8.3, and 3.5 +/- 5.3 mg/dL in type I, IV, and V, respectively; P < .01 v controls).(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of resistance to dietary cholesterol in the rat after hypophysectomy: importance of the presence of growth hormone for hepatic low density lipoprotein-receptor expression

This investigation was undertaken to determine the role of pituitary function and, in particular, the possible influence of growth hormone (GH) on hepatic low density lipoprotein (LDL)-receptor expression in response to dietary cholesterol. Feeding normal rats with 2% cholesterol for 5 or 6 days did not alter LDL-receptor numbers, LDL-receptor mRNA levels, or plasma cholesterol, although hepatic cholesterol increased 5-fold. When hypophysectomized rats received the same diet, the LDL-receptor number and its mRNA levels were reduced by 75%, plasma cholesterol increased 6-fold, and hepatic cholesterol increased 12-fold. Stepwise hormonal substitution of cholesterol-fed, hypophysectomized rats revealed that substitution with GH was important to restore hepatic LDL-receptor number and mRNA levels. The presence of GH was also important to reduce the hypercholesterolemia in cholesterol-fed hypophysectomized rats. We conclude that the presence of GH is important for hepatic LDL-receptor expression, both at the protein and the mRNA level. The resistance to suppression of rat hepatic LDL receptors by dietary cholesterol depends, at least in part, on the presence of GH.

Detection of premature atherosclerosis by high-resolution ultrasonography in symptom-free hypopituitary adults

Retrospective analysis suggests that there is increased mortality from vascular disease in hypopituitary adults, but vascular status before death is unknown. High resolution B-mode ultrasonic imaging of both carotid and femoral arteries was therefore done in 34 adult hypopituitary patients on routine replacement therapy and was compared with that in 39 matched controls. Changes were related to risk factors for vascular disease. Carotid intima-media thickness was greater in patients than in controls (mean [SD] 0.74 [0.16] vs 0.65 [0.13] mm, p < 0.02). This difference was seen in middle-aged and elderly patients. More patients than controls had one or more atheromatous plaques (65% vs 41%, p < 0.05). The percentage of individual arteries with a plaque was also higher in patients (32% vs 18%, p < 0.005). In multiple regression analysis, patients' age was the dominant factor determining carotid intima-media thickness. Symptom-free adults with hypopituitarism show an increased prevalence of atherosclerosis.

A rapid electrophoretic method for the detection of serum Lp(a) lipoprotein

A rapid electrophoretic method detecting serum lipoprotein(a) (Lp(a)) was described. When serum lipoproteins were electrophoresed using an agarose gel film containing 0.6% agarose and 3% sucrose, a distinct extra-band was frequently detected between beta- and prebeta-bands. This lipoprotein band was identified as Lp(a) by immunoblotting technique using anti-Lp(a) serum. Using this electrophoretic method, we studied 1,353 subjects with a variety of diseases. The Lp(a)-positive subjects accounted for 8.4% of all. Neither sex nor age influenced the frequency of Lp(a) positivity. Frequencies of definite myocardial infarction in Lp(a)-positive subjects did not differ significantly from those in Lp(a)-negative ones. Those of cerebral infarction in Lp(a)-positive subjects were significantly higher than those in Lp(a)-negative ones. An electrophoretic method described herein is very useful for the rapid detection and screening of Lp(a), and hence for large-scale clinical studies of atherosclerotic risk assessment.

Sheehan's syndrome presenting with type III hyperlipoproteinaemia

A patient is described in whom the presenting feature of hypopituitarism was the development of palmar xanthomata associated with type III hyperlipoproteinaemia. Treatment of her secondary hypothyroidism with thyroxine caused resolution of the xanthomata and hyperlipidaemia, but the underlying compositional abnormality of the lipoproteins could still be observed.

Potential therapeutic indications for growth hormone and growth hormone-releasing hormone in conditions other than growth retardation

Growth hormone (GH) previously was available in limited supply and only for the treatment of GH-deficient children. The recent production of GH by recombinant DNA technology has provided a potential surfeit of this hormone and raises the possibility of its use in other conditions. In addition, the isolation, characterization, and synthesis of GH-releasing hormone (GRH) provides an opportunity to use this peptide in conditions in which increased circulating levels of GH are desired. Both GH and GRH have potential therapeutic uses in conditions other than growth retardation.