Can LDL cholesterol be too low? Possible risks of extremely low levels.

Following the continuous accumulation of evidence supporting the beneficial role of reducing low-density lipoprotein cholesterol (LDL-C) levels in the treatment and prevention of atherosclerotic cardiovascular disease and its complications, therapeutic possibilities now exist to lower LDL-C to very low levels, similar to or even lower than those seen in newborns and nonhuman species. In addition to the important task of evaluating potential side effects of such treatments, the question arises whether extremely low LDL-C levels per se may provoke adverse effects in humans. In this review, we summarize information from studies of human cellular and organ physiology, phenotypic characterization of rare genetic diseases of lipid metabolism, and experience from clinical trials. Specifically, we emphasize the importance of the robustness of the regulatory systems that maintain balanced fluxes and levels of cholesterol at both cellular and organismal levels. Even at extremely low LDL-C levels, critical capacities of steroid hormone and bile acid production are preserved, and the presence of a cholesterol blood-brain barrier protects cells in the central nervous system. Apparent relationships sometimes reported between less pronounced low LDL-C levels and disease states such as cancer, depression, infectious disease and others can generally be explained as secondary phenomena. Drug-related side effects including an increased propensity for development of type 2 diabetes occur during statin treatment, whilst further evaluation of more potent LDL-lowering treatments such as PCSK9 inhibitors is needed. Experience from the recently reported and ongoing large event-driven trials are of great interest, and further evaluation including careful analysis of cognitive functions will be important.

HDL and LDL as therapeutic targets for cardiovascular disease prevention: the possible role of niacin.

Recently two studies on the effect of addition of extended-release niacin to statin treatment on measures of carotid atherosclerosis were estimated in the ARBITER 6-HALTS study (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 6-HDL and LDL Treatment Strategies) study and the Oxford Niacin Study were published. Adding niacin to statin treatment significantly diminished carotid atherosclerosis as measured by ultrasound carotid intima-media thickness or magnetic resonance imaging. An inhibitor of niacin induced flushing, laropiprant has been developed and demonstrated to considerably improve the tolerability of niacin therapy without impeding on its effect on lipoproteins. Still however clear evidence for the clinical benefit of long-term niacin treatment on cardiovascular morbidity and mortality is lacking. The development situation for ezetimibe is similar to that of niacin. Long-term interventional studies with hard endpoints of both therapies are ongoing. Also both drugs, when proven efficient and safe, are eagerly needed in the prevention of cardiovascular disease.

Cardiovascular outcomes and their relationships to lipoprotein components in patients with and without chronic kidney disease: results from the IDEAL trial.

OBJECTIVES: In Incremental Decrease in Endpoints through Aggressive Lipid-lowering (IDEAL), we compared cardiovascular outcomes in patients with and without chronic kidney disease (CKD) (estimated glomerular filtration rate <60 mL min(-1) 1.73 m(-2)) and analysed relationships between lipoprotein components (LC) and major coronary events (MCE) and other cardiovascular (CV) events. DESIGN: Exploratory analysis of CV endpoints in a randomized trial comparing high dose of atorvastatin to usual dose of simvastatin on MCE. SETTINGS: Patients with CKD were compared with the non-CKD patients. Cox regression models were used to study the relationships between on-treatment levels of LC and incident MCE. FINDINGS: Chronic kidney disease was strongly associated with cardiovascular end-points including total mortality. In patients with CKD, a significant benefit of high dose atorvastatin treatment was found for any CV events, stroke and peripheral artery disease, but not for MCE. However, all cardiovascular end-points except stroke and CV mortality were reduced in the non-CKD group. Differential changes in LC or relationships to LC could not explain the different treatment outcomes in MCE in the two groups. INTERPRETATION: Chronic kidney disease was a powerful risk factor for all cardiovascular end-points. The reason why the significant reductions achieved by high-dose statin treatment in most CV end-points in the non-CKD group were only in part matched by similar reductions in the CKD patients is not apparent. This difference did not result from differential changes in or relations to LC, but limited power may have increased the possibility of chance findings.

Well-being in patients with amyotrophic lateral sclerosis and their next of kin over time.

OBJECTIVES: The well-being and physical function among patients with ALS and their next of kin was studied over time. MATERIALS AND METHODS: Thirty-five patients with ALS and their next of kin were studied with respect to physical, general and psychological well-being by the visual analogue scale (VAS) every 4-6 months. Physical function in patients was rated by the ALSFRS-R and the Norris scale. Patients and next of kin rated the well-being of themselves and their counterpart. RESULTS: The well-being was stable and there was a relation between the well-being of patients and next of kin throughout the time studied. Next of kin rated the well-being of the patients worse than patients rated themselves, while patients rated the well-being of their next of kin at the same level as their counterpart. CONCLUSIONS: The basic state of well-being as well as the interaction between patient and next of kin seem to be factors that influence the well-being of both patients and their next of kin.

Lipid-modifying efficacy and tolerability of extended-release niacin/laropiprant in patients with primary hypercholesterolaemia or mixed dyslipidaemia.

BACKGROUND: Improving lipids beyond low-density lipoprotein cholesterol (LDL-C) lowering with statin monotherapy may further reduce cardiovascular risk. Niacin has complementary lipid-modifying efficacy to statins and cardiovascular benefit, but is underutilised because of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). Laropiprant (LRPT), a PGD(2) receptor (DP1) antagonist that reduces niacin-induced flushing has been combined with extended-release niacin (ERN) into a fixed-dose tablet. METHODS AND RESULTS: Dyslipidaemic patients were randomised to ERN/LRPT 1 g (n = 800), ERN 1 g (n = 543) or placebo (n = 270) for 4 weeks. Doses were doubled (2 tablets/day; i.e. 2 g for active treatments) for 20 weeks. ERN/LRPT 2 g produced significant changes vs. placebo in LDL-C (-18.4%), high-density lipoprotein cholesterol (HDL-C; 20.0%), LDL-C:HDL-C (-31.2%), non-HDL-C (-19.8%), triglycerides (TG; -25.8%), apolipoprotein (Apo) B (-18.8%), Apo A-I (6.9%), total cholesterol (TC; -8.5%), TC:HDL-C (-23.1%) and lipoprotein(a) (-20.8%) across weeks 12-24. ERN/LRPT produced significantly less flushing than ERN during initiation (week 1) and maintenance (weeks 2-24) for all prespecified flushing end-points (incidence, intensity and discontinuation because of flushing). Except for flushing, ERN/LRPT had a safety/tolerability profile comparable with ERN. CONCLUSION: Extended-release niacin/LRPT 2 g produced significant, durable improvements in multiple lipid/lipoprotein parameters. The improved tolerability of ERN/LRPT supports a simplified 1 g-->2 g dosing regimen of niacin, a therapy proven to reduce cardiovascular risk.

Impaired cortisol response to acute stressors in patients with coronary disease. Implications for inflammatory activity.

OBJECTIVES: Inflammation is assumed to play a major role in the progress of atherosclerotic disease. We hypothesized that an altered hypothalamic-pituitary adrenal (HPA) axis activity was linked to a disinhibited inflammatory activity in patients with coronary artery disease (CAD). METHODS: Thirty CAD patients were assessed 12-14 weeks after a first-time acute coronary syndrome. Serum samples were assayed for C-reactive protein (CRP) and interleukin-6. Free cortisol was measured in a 24-h urine sample and in repeated saliva samples 30 min after awakening and at bedtime. The levels of inflammatory markers and cortisol were also determined before and after standardized physical and psychological stress tests. RESULTS: The CAD patients had a higher 24-h cortisol secretion and a flattened diurnal slope, resulting from significantly higher cortisol levels at bedtime, compared to clinically healthy controls. The levels of evening cortisol were strongly related to inflammatory markers in serum. When exposed to acute physical and psychological stressors, the CAD patients showed a significantly blunted cortisol response compared to controls. In addition, a stress-induced increase in CRP was only observed in the patient group. CONCLUSIONS: Patients with CAD exhibited a cortisol pattern that markedly differed from controls. The data indicate that a dysfunctional HPA axis response involves a failure to contain inflammatory activity in CAD patients, thus providing a possible link between stress and inflammation in disease.

Long-term cardiac outcomes in renal transplant recipients receiving fluvastatin: the ALERT extension study.

Renal transplant recipients (RTR) have an increased risk of premature cardiovascular disease. The ALERT study is the first trial to evaluate the effect of statin therapy on cardiac outcomes following renal transplantation. Patients initially randomized to fluvastatin or placebo in the 5-6 year ALERT study were offered open-label fluvastatin XL 80 mg/day in a 2-year extension to the original study. The primary endpoint was time to first major adverse cardiac event (MACE). Of 1787 patients who completed ALERT, 1652 (92%) were followed in the extension. Mean total follow-up was 6.7 years. Mean LDL-cholesterol was 98 mg/dL (2.5 mmol/L) at last follow-up compared to a pre-study level of 159 mg/dL (4.1 mmol/L). Patients randomized to fluvastatin had a reduced risk of MACE (hazards ratio [HR] 0.79, 95% CI 0.63-0.99, p = 0.036), and a 29% reduction in cardiac death or definite non-fatal MI (HR 0.71, 95% CI 0.55-0.93, p = 0.014). Total mortality and graft loss did not differ significantly between groups. Fluvastatin produces a safe and effective reduction in LDL-cholesterol associated with reduced risk of MACE in RTR. The lipid-lowering and cardiovascular benefits of fluvastatin are comparable to those of statins in other patient groups, and support use of fluvastatin in RTR.

Autosomal recessive hypercholesterolaemia: normalization of plasma LDL cholesterol by ezetimibe in combination with statin treatment.

BACKGROUND: Severe hereditary hypercholesterolaemia is most frequently due to familial hypercholesterolaemia (FH), caused by mutations in the LDL receptor (LDLR) gene. However, a phenotype very similar to FH may also be caused by defects in other genes like the genes for apolipoprotein (apo) B-100 or autosomal recessive hypercholesterolaemia (ARH). SUBJECT: An 8-year-old male of Lebanese origin was diagnosed with severe hypercholesterolaemia and extensive cutaneous and tendon xanthomas. Plasma LDL cholesterol before treatment was 17 mmol L(-1), whilst parents and both siblings had normal levels. DIAGNOSIS: Degradation of (125)I-labelled LDL in blood lymphocytes was reduced, but not abolished. Sequencing analysis of the LDLR and apoB-100 genes were negative, whilst a splice acceptor mutation in intron 1 (IVS 1 -1G>C) was detected in the ARH gene. The patient was homozygous for the mutation, whilst the parents were heterozygous. These findings were in agreement with a diagnosis of ARH. TREATMENT AND CLINICAL COURSE: Monthly LDL apheresis and atorvastatin 120 mg daily reduced LDL cholesterol preapheresis level to 4.8 mmol L(-1). When ezetimibe was given 10 mg day(-1) in combination with rosuvastatin 80 mg day(-1), LDL cholesterol was further lowered to 1.6 mmol L(-1), which made apheresis unnecessary. Cutaneous and tendon xanthomas disappeared completely and the intima-media thickness of the common carotid arteries decreased. At age 23 he developed a small myocardial infarction. CONCLUSION: ARH should be considered in cases of severe hypercholesterolaemia with a pattern of recessive inheritance. Combination therapy with high-dose statin and ezetimibe seems to be the treatment of choice in ARH and may reduce or eliminate the need for LDL apheresis treatment.

Low serum beta-carotene reflects immune activation in patients with coronary artery disease.

BACKGROUND AND AIM: Low serum levels of antioxidant vitamins are associated with coronary artery disease (CAD). An immunomodulatory effect of antioxidants has been proposed. The aim of the study was to investigate whether an increased immune response in CAD patients was associated with suppressed circulating levels of antioxidant vitamins. METHODS AND RESULTS: Forty-four men with stable angina and angiographically verified CAD were included as well as 69 healthy controls. T cell subsets in peripheral blood were quantified by 3-colour flow cytometry. C-reactive protein (CRP), soluble interleukin-2 receptor (sIL-2R) and the lipophilic antioxidants alpha-tocopherol, beta-carotene and lycopene were determined in serum. Compared with controls, patients had signs of an enhanced inflammatory activity assessed by significantly increased levels of CRP, sIL-2R and CD4+CD25+T cell subsets. Patients also had significantly lower beta-carotene and lycopene levels whereas a-tocopherol levels did not differ. The increased inflammatory/immune parameters in patients showed a significant inverse relationship to serum beta-carotene but not to lycopene or alpha-tocopherol. CONCLUSIONS: Low serum beta-carotene in CAD patients reflects activation of the immune system. Inflammation should be considered as an important confounding factor when analysing data on beta-carotene and CAD.

Differential recruitment of the coactivator proteins CREB-binding protein and steroid receptor coactivator-1 to peroxisome proliferator-activated receptor gamma/9-cis-retinoic acid receptor heterodimers by ligands present in oxidized low-density lipoprotein.

Peroxisome proliferator-activated receptor gamma (PPARgamma) colocalizes with oxidized low-density lipoprotein (LDL) in foam cells in atherosclerotic lesions. We have explored a potential role of oxidized fatty acids in LDL as PPARgamma activators. LDL from patients suffering from intermittent claudication due to atherosclerosis was analyzed using HPLC and gas chromatography/mass spectrophotometry and found to contain 9-hydroxy and 13-hydroxyoctadecadienoic acid (9- and 13-HODE), as well as 5-hydroxy-, 12-hydroxy- and 15-hydroxyeicosatetraenoic acid (5-, 12- and 15-HETE respectively). PPARgamma was potently activated by 13(S)-HODE and 15(S)-HETE, as judged by transient transfection assays in macrophages or CV-1 cells. 5(S)- and 12(S)-HETE as well as 15-deoxy-Delta(12,14)-prostaglandin J(2) also activated PPARgamma but were less potent. Interestingly, the effect of the lipoxygenase products 13(S)-HODE and 15(S)-HETE as well as of the drug rosiglitazone were preferentially enhanced by the coactivator CREB-binding protein, whereas the effect of the cyclooxygenase product 15-deoxy-Delta(12,14)-prostaglandin J(2) was preferentially enhanced by steroid receptor coactivator-1. We interpret these results, which may have relevance to the pathogenesis of atherosclerosis, to indicate that the lipoxygenase products on the one hand and the cyclooxygenase product on the other exert specific effects on the transcription of target genes through differential coactivator recruitment by PPARgamma/9-cis retinoic acid receptor heterodimer complexes.

Familial hypercholesterolaemia and quality of life in family members.

BACKGROUND: Awareness of genetic disease in the family may influence quality of life. The purpose of this study was to describe quality of life among nonaffected members of families with familial hypercholesterolaemia. All were aware of the risk for coronary heart disease. Their quality of life was compared with a reference group and with the patients with familial hypercholesterolaemia themselves. METHODS: Names of family members (n = 129) were given by the patients with familial hypercholesterolaemia. A randomly selected reference group (n = 1485) and patients with familial hypercholesterolaemia (n = 185) were included for comparison. They all completed the questionnaire Quality of Life Index, the Hospital Anxiety and Depression Scale, and the Mastery Scale measuring coping. Family members and patients with familial hypercholesterolaemia also completed a questionnaire on health and lipids. RESULTS: Family members were more satisfied with family life, mean 22.1 +/- 3.5 (SD), and psychological/spiritual life, 22.9 +/- 4.0, than the reference group, 21.4 +/- 4.3 and 21.1 +/- 4.8, respectively; this was particularly expressed among partners, P < 0.05. Of family members, 91% were anxious about the patient with familial hypercholesterolaemia developing coronary heart disease. CONCLUSIONS: Family members have as good a quality of life as members of the reference group, but they were anxious about the patient with familial hypercholesterolaemia developing coronary heart disease.

Monocyte chemoattractant protein-1 and CC-chemokine receptor-2 in severe hypercholesterolaemia.

OBJECTIVES: To investigate whether plasma concentrations of monocyte chemoattractant protein-1 (MCP-1) and the gene expression of its receptor on the monocyte cell surface CCR-2 were elevated above normal in subjects with asymptomatic, isolated hypercholesterolaemia and if statin treatment could influence this cytokine. METHODS: The investigation was designed as a cross sectional study followed by a single, blind, treatment study of patients receiving pravastatin 80 mg/day for 8 weeks. The study included 23 patients with severe hypercholesterolaemia (LDL>5.2 mmol/L) and 39 normocholesterolaemic controls. Blood samples were obtained from patients and controls at baseline and from patients at end of the study and analysed for lipoproteins and inflammatory mediators: MCP-1. high-sensitivity C-reactive protein (HS-CRP). Isolated peripheral mononuclear cells were analysed for CCR-2 gene expression. RESULTS: Mean plasma LDL-C was significantly higher in patients than in controls. No difference in plasma MCP-1 levels or CCR-2 gene expression was seen between the groups at baseline, nor were there any differences in plasma concentrations of CRP. After treatment with pravastatin, LDL-C decreased by 31%. Treatment did not significantly affect the levels of MCP-1 or CCR-2 gene expression, nor was CRP affected by treatment with pravastatin. CONCLUSIONS: Our study does not support the view that MCP-1 plasma levels and CCR-2 gene expression in circulating monocytes are directly responsible for the monocyte recruitment into the arterial intima in patients with severe asymptomatic hypercholesterolaemia. In addition, the inflammatory response of a high concentration of LDL-C in isolated asymptomatic hypercholesterolaemia is minute.

Long chain polyunsaturated fatty acids may account for higher low-density lipoprotein oxidation susceptibility in Lithuanian compared to Swedish men.

OBJECTIVES: Mortality in coronary heart disease among middle-aged men is four times higher in Lithuania than in Sweden. Traditional risk factors cannot account for this difference. We earlier reported that low-density lipoprotein (LDL) in Lithuanian men showed a lower resistance to oxidation, measured as LDL lag time during copper oxidation, than that in Swedish men. Serum concentrations of several fat-soluble antioxidant vitamins were lower among Lithuanian men. The aim of this study was to investigate whether differences in LDL fatty acid composition could account for the difference in LDL oxidation susceptibility between men in the two countries. METHODS: This cross-sectional study included randomly selected healthy 50-year-old men from Vilnius, Lithuania (n=50) and Linköping, Sweden (n=50). Main outcome measures were fatty acids in LDL, phospholipid (PL) and cholesterol ester (CE) fractions of LDL and LDL oxidation susceptibility. RESULTS: The mean proportions of PL 20:5n3 (eicosapentaenoic acid, EPA) were higher in Vilnius men (2.09 +/- 1.05 vs. 1.53 +/- 0.58%, p= 0.004). LDL lag time was shorter in Vilnius men, mean +/- SD (75.4 +/- 13.6 vs. 89.5 +/- 13.1 mins, p<0.0001) than in Linköping men. Mean serum gamma-tocopherol was lower in Vilnius men (0.07 +/- 0.05 vs. 0.12 +/- 0.04 microg/mmol, p<0.0001) but alpha-tocopherol did not differ. In a multiple regression analysis controlled for city, high PL-EPA, low alpha-tocopherol, and high plasma triglycerides significantly contributed to a short LDL lag time, r2=0.53. CONCLUSIONS: Fat quality, i.e. poly unsaturated fatty acids, especially LDL-EPA, plasma triglycerides and antioxidative vitamins may partly account for the increased LDL oxidation susceptibility found in Vilnius men compared with Linköping men.

Are early clinical effects of cholesterol lowering mediated through effects on inflammation?

In a randomized, double-blind trial in 3086 patients with unstable angina pectoris or non-Q wave myocardial infarction we investigated if 80 mg of atorvastatin daily could improve outcome of cardiovascular events during a short period of time (16 weeks) compared with placebo. Baseline LDL cholesterol was 3.2 mmol L-1 (124 mg dL-1) and decreased by 40% to 1.9 mmol L-1 (72 mg dL-1) during atorvastatin treatment. The primary endpoint, which was a composite of death, non-fatal acute myocardial infarction, cardiac arrest with resuscitation or recurrent symptomatic myocardial ischaemia with objective evidence and requiring emergency rehospitalization occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group. The relative risk was 0.84 and 95% confidence interval was 0.70-1.00 (P = 0.048). Thus for patients with acute coronary syndromes, lipid-lowering therapy with high dose atorvastatin reduces recurrent ischaemic events in the short-term. A possible mechanism behind this rapid clinical effect induced by statin treatment is on inflammatory processes. Recent studies strongly suggest that acute T-cell activation is involved in the pathogenesis of unstable angina. In another study we investigated whether circulating T cells showed signs of activation in patients with stable angina pectoris (SA). Systemic venous blood samples were taken from 38 men with SA and 42 healthy controls. The T-cell receptor expression was assessed by three-colour flow cytometry using monoclonal antibodies against CD3,CD4, CD8, CD25 and human leucocyte antigen (HLA)-DR. Soluble interleukin-2 receptor (sIL-2R) was measured as the circulating form in serum. Levels of circulating CD3+ and CD4+ T cells tended to be higher in patients compared with controls. Patients were also shown to have a significant increase in CD4+ T cells expressing the activation markers CD25 (P < 0.05) and HLA-DR (P < 0.01). Furthermore, serum levels of sIL-2R were significantly higher (P < 0.001) in patients than in controls. We also observed that the T-cell response was more pronounced in patients without simvastatin treatment (n = 18) compared with simvastatin-treated patients (n = 20). In conclusion, our findings indicate that a continuous immune system activation takes place in patients with chronic angina pectoris, predominantly involving proliferation of CD4+ T cells. Statin treatment seems to be able to decrease this inflammatory response.

Management of hypercholesterolaemia in the patient with diabetes.

Coronary heart disease (CHD) is the leading cause of death in patients with type 2 diabetes. The hyperglycaemia that characterises this disease is often accompanied by a cluster of other risk factors, such as dyslipidaemia and hypertension, and effective management of the patient with diabetes requires treatment directed at correcting all of the abnormalities that increase cardiovascular risk. Approximately 90% of patients with diabetes have type 2 disease, and dyslipidaemia in these patients is characterised by elevated plasma triglycerides and very-low-density lipoproteins (VLDL), by reduced high-density lipoprotein cholesterol (HDL-C), and by a shift in LDL distribution towards small, dense particles. All of these lipid abnormalities are important risk factors for CHD. Retrospective subgroup analysis and prospective studies have shown that lipid-lowering therapy can slow the progression of atherosclerosis and reduce the risk for cardiovascular events in patients with diabetes, and both the National Cholesterol Education Program Adult Treatment Panel III and American Diabetes Association have established aggressive treatment goals for lipid-lowering therapy in these patients. All of the major medications used to treat hyperlipidaemia in other populations (niacin, fibrates, bile acid sequestrants and statins) have been used effectively to improve the plasma lipid profile in patients with diabetes. Statins are generally accepted as first-line treatment for these patients, although fibrates also have an important role in patients with pronounced hypertriglyceridaemia. Statins significantly reduce low-density lipoprotein cholesterol (LDL-C) in a broad range of patients. These agents also have substantial effects on plasma triglycerides and, in patients with hypertriglyceridaemia, lower very-low-density lipoprotein cholesterol (VLDL-C) to approximately the same extent as LDL-C. In this regard, the new agent rosuvastatin has been shown, in recent trials, to produce greater decreases in these lipoproteins than currently marketed compounds. Aggressive use of agents that attack the lipid abnormalities characteristic of patients with type 2 diabetes has the potential to significantly reduce CHD risk in these individuals.

A dose titration model for recombinant GH substitution aiming at normal plasma concentrations of IGF-I in hypopituitary adults.

OBJECTIVE: To evaluate a dose titration model for recombinant human GH substitution in adult patients with GH deficiency, aiming at normal plasma levels of IGF-I. DESIGN AND METHODS: Eighteen patients participated and a start dose of 0.17 mg GH/day was used except by two men who started with 0.33 mg/day. To demonstrate a clear GH effect the patients were first titrated, with steps of 0.17 mg GH/day every 6-8 weeks, to IGF-I levels in the upper range of age-adjusted reference values. The GH dose was then reduced 1 dose step and kept for a further 6 months. For comparison we investigated 17 healthy control subjects. RESULTS: Plasma IGF-I was increased after 2 weeks on the start dose and did not increase further for up to 8 weeks. Women had significantly lower GH sensitivity than men measured as net increment of IGF-I on the start dose of GH. GH sensitivity was not changed by age. The plasma IGF-I levels increased from 76.3+/-47.0 (s.d.) to 237+/-97 microg/l at the end of the study (P<0.001), and similar IGF-I levels were obtained in both sexes. The maintenance median GH dose was 0.33 mg/day in males and 0.83 mg/day in females (P=0.017). The GH dose correlated negatively with age in both sexes. Body weight, very low density triglycerides, lipoprotein(a) (Lp(a)), and fasting insulin increased, whereas insulin sensitivity index (QUICKI) decreased significantly. In comparison with the controls, the patients had lower fasting blood glucose, fasting insulin and Lp(a) levels at baseline, but these differences disappeared after GH substitution. The two groups had equal insulin sensitivity (QUICKI), but 2 h oral glucose tolerance test values of blood glucose and insulin were significantly higher in the patients at the end of the study. CONCLUSIONS: In conclusion our data suggest that the starting dose of GH substitution and the dose titration steps should be individualised according to GH sensitivity (gender) and the IGF-I level aimed for (age). The reduced insulin sensitivity induced by GH substitution could be viewed as a normalisation if compared with control subjects.