Macrocytic anemia in Lesch-Nyhan disease and its variants.

PURPOSE: Lesch-Nyhan disease is an inherited metabolic disorder characterized by overproduction of uric acid and neurobehavioral abnormalities. The purpose of this study was  to describe macrocytic erythrocytes as another common aspect of the phenotype. METHODS: The results of 257 complete blood counts from 65 patients over a 23-year period were collected from 2 reference centers where many patients are seen regularly. RESULTS: Macrocytic erythrocytes occurred in 81-92% of subjects with Lesch-Nyhan disease or its neurological variants. After excluding cases with iron deficiency because it might pseudonormalize erythrocyte volumes, macrocytosis occurred in 97% of subjects. Macrocytic erythrocytes were sometimes accompanied by mild anemia, and rarely by severe anemia. CONCLUSION: These results establish macrocytic erythrocytes as a very common aspect of the clinical phenotype of Lesch-Nyhan disease and its neurological variants. Macrocytosis is so characteristic that its absence should prompt suspicion of a secondary process, such as iron deficiency. Because macrocytosis is uncommon in unaffected children, it can also be used as a clue for early diagnosis in children with neurodevelopmental delay. Better recognition of this characteristic feature of the disorder will also help to prevent unnecessary diagnostic testing and unnecessary attempts to treat it with folate or B12 supplements.

A double-blind, placebo-controlled, crossover trial of the selective dopamine D1 receptor antagonist ecopipam in patients with Lesch-Nyhan disease.

Lesch-Nyhan disease (LND) is a genetic disorder that has characteristic metabolic, neurologic, and behavioral features. There are multiple behavioral problems including impulsivity, aggressiveness, and severe recurrent self-injurious behavior (SIB). This last behavior varies considerably across subjects and may encompass self-biting, self-hitting, scratching, head banging, and other injurious actions. Current treatments for SIB involve behavioral extinction, sedatives, physical restraints, and removal of teeth. Because these interventions do not reliably control SIB, better treatments are urgently needed. Animal studies have suggested that D1-dopamine receptor antagonists such as ecopipam may suppress SIB. These observations have led to proposals that such drugs might provide effective treatment for in LND. The current study describes the results of a double-blind, three-period, crossover trial of a single dose of ecopipam in subjects with LND. The study was designed for 20 patients, but it was terminated after recruitment of only 10 patients, because interim analysis revealed unanticipated side effects. These side effects were most likely related to starting with a single large dose without any titration phase. Despite the limited data due to early termination, the drug appeared to reduce SIB in most cases. Subjects who completed the trial were eligible to continue the drug in an open-label extension phase lasting a year, and one patient who elected to continue has maintained a striking reduction in SIB for more than a year with no apparent side effects. These results suggest ecopipam could be a useful treatment for SIB in, but further studies are needed to establish an appropriate dosing regimen.

Mechanisms for phenotypic variation in Lesch-Nyhan disease and its variants.

Lesch-Nyhan disease is a neurogenetic disorder caused by mutation of the HPRT1 gene on the X chromosome. There is significant variation in the clinical phenotype, with more than 300 different known mutations. There are few studies that have addressed whether similar mutations result in similar phenotypes across different patients because hypoxanthine-guanine phosphoribosyltransferase (HGprt) deficiency is rare, and most mutations are unique or limited to individual families. However, recent studies have revealed multiple unrelated patients with similar mutations, providing an opportunity to examine genotype-phenotype correlations. We found significant variation among the clinical features of 10 patients from 8 unrelated families all carrying a mutation replacing guanine with adenine at base position 143 (c.143G>A) in the HPRT1 gene. This mutation results in replacement of arginine by histidine at amino acid position 48 (p.arg48his) in the HGprt enzyme. Biochemically, the enzyme exhibits reduced thermal integrity, a mechanism that may explain clinical variation. The literature reveals similar clinical variation among other patients with similar mutations, although the variation is relatively minor across the whole population of patients. Identifiable sources of clinical variation include known limitations of clinical ascertainment and mechanisms that affect residual enzyme activity and stability. These results are helpful for understanding genotype-phenotype correlations and discordance and likely are applicable to other neurogenetic disorders where similar variation occurs.

Efficacy of indapamide SR compared with enalapril in elderly hypertensive patients with type 2 diabetes.

BACKGROUND: Blood pressure control is the main influential variable in reducing microalbuminuria in patients with type 2 diabetes. In this subanalysis of the Natrilix SR versus Enalapril Study in hypertensive Type 2 diabetics with micrOalbuminuRia (NESTOR) study, we have compared the effectiveness of indapamide sustained release (SR) and enalapril in reducing blood pressure and microalbuminuria in patients > or =65 years of age. METHODS: Of the 570 hypertensive patients with type 2 diabetes and persistent microalbuminuria in the NESTOR study, 187 (33%) individuals > or =65 years of age were included in this analysis. Of these, 95 patients received indapamide SR 1.5 mg and 92 patients received enalapril 10 mg, taken once daily in both cases. Adjunctive amlodipine and/or atenolol was added if required. RESULTS: The urinary albumin-to-creatinine ratio decreased by 46% in the indapamide SR group and 47% in the enalapril group. Noninferiority of indapamide SR over enalapril was demonstrated (P = .0236; 35% limit of noninferiority) with a ratio of 0.95 (95% CI: 0.68, 1.34). Mean arterial pressure decreased by 18 mm Hg and 15 mm Hg in the indapamide SR and the enalapril groups, respectively (P = .1136). The effects of both treatments seen in these elderly patients were similar to those observed in the main population, although the extent of the reduction in microalbuminuria was slightly higher. Both treatments were well tolerated, and no difference between groups was observed regarding glucose or lipid profiles. CONCLUSION: Indapamide SR is not less effective than enalapril in reducing microalbuminuria and blood pressure in patients aged >65 years of age with type 2 diabetes and hypertension.

Uric acid and oxidative stress: relative impact on cardiovascular risk?

Post-hoc analyses of the GREACE and the LIFE trials have renewed the interest in elevated serum uric acid (SUA) as a factor contributing to atherosclerotic cardiovascular disease (CVD) and in the possible benefit derived from its pharmacological reduction. The results of these trials are consistent with reports indicating favourable effects of SUA lowering treatment with allopurinol on the rate of cardiovascular complications in patients with coronary heart disease, congestive heart failure and dilated cardiomyopathy. Two recent overviews have concluded that, while in population samples at relatively low risk of CVD, SUA is at best a very weak predictor of CVD, by contrast it is a significant independent predictor among subjects at high or very high risk. This raises the question of a different meaning of excess SUA levels under different circumstances. Whereas in uncomplicated obese, insulin-resistant and hypertensive patients SUA levels increase mainly as a consequence of impaired renal excretion, in conditions of local ischemia an increased production of uric acid occurs in parallel with that of reactive oxygen species (ROS). Thus, although clinical and experimental evidence suggest that uric acid has actually antioxidant properties, it is conceivable that under these conditions its antioxidant activity is overcome by the pro-oxidant and pro-inflammatory effects of ROS accumulation. At present, there is no solid evidence to recommend treatment of the mild asymptomatic hyperuricemia associated with obesity, diabetes and/or hypertension (up to 10mg/dL). By contrast, similar SUA elevations in patients at higher cardiovascular risk should be taken more seriously. A controlled trial to investigate the effects of SUA reduction in these patients, while monitoring concomitant changes in parameters of oxidative stress and inflammation, is warranted.

Comprehensive cardiovascular risk management--what does it mean in practice?

The continued movement away from the treatment of individual cardiovascular (CV) risk factors to managing overall and lifetime CV risk is likely to have a significant impact on slowing the rate of increase in cardiovascular disease (CVD). However, the management of CVD is currently far from optimal even in parts of the world with well-developed and well-funded healthcare systems. Effective implementation of the knowledge, treatment guidelines, diagnostic tools, therapeutic interventions, and management programs that exist for CVD continues to evade us. A thorough understanding of the multifactorial nature of CVD is essential to its effective management. Improvements continue to be made to management guidelines, risk assessment tools, treatments, and care programs pertaining to CVD. Ultimately, however, preventing the epidemic of CVD will require a combination of both medical and public health approaches. In addition to improvements in the "high-risk" strategy, which forms the basis of current CVD management, an increase in the utilization of population-based management strategies needs to be made to attempt to reduce the number of patients falling within the "at-risk" stratum for CVD. This review outlines how a comprehensive approach to CVD management might be achieved.

Felodipine-metoprolol combination tablet: maintained health-related quality of life in the presence of substantial blood pressure reduction.

BACKGROUND: Most treated hypertensive patients do not achieve adequate blood pressure (BP) control. Initiating therapy with two drugs has been suggested when BP is >20/10 mm Hg above goal. To ensure patients' compliance, such treatment needs to be well tolerated and must not compromise health-related quality of life (HRQL). The primary objective of this study was to compare the effects on HRQL of initiating treatment with felodipine + metoprolol (F+M) fixed combination tablets, or enalapril (E), or placebo (P). METHODS: A total of 947 patients of both sexes with primary hypertension (diastolic BP 95 to 110 mm Hg), aged 20 to 70 years, participated in this randomized, double-blind, parallel group, 12-week, multicenter trial. Treatment was initiated with F+M 5 + 50 mg, or E 10 mg, or P. Doses were doubled after 4 or 8 weeks if diastolic BP was >90 mm Hg. The HRQL was measured at baseline and at the last visit using two validated questionnaires: the Psychological General Well-being Index (PGWB) and the Subjective Symptom Assessment Profile (SSA-P). Office BP was measured at trough, that is, 24 h after the previous dose. RESULTS: The HRQL was high at baseline and generally well maintained during the study. For example, the mean (SD) PGWB total score was 104 (16) at baseline and 105 (16) at 12 weeks in all three treatment groups. The BP reductions after F+M (18/14 mm Hg) and E (12/9 mm Hg) were significantly greater than after P (7/7 mm Hg), and the reduction after F+M was significantly greater than after E. CONCLUSIONS: The HRQL is maintained in the presence of substantial BP reduction during antihypertensive treatment with F+M fixed combination tablets.

Familial juvenile hyperuricaemic nephropathy (FJHN): linkage analysis in 15 families, physical and transcriptional characterisation of the FJHN critical region on chromosome 16p11.2 and the analysis of seven candidate genes.

Familial juvenile hyperuricaemic nephropathy (FJHN) is an autosomal dominant renal disease characterised by juvenile onset of hyperuricaemia, gouty arthritis, and progressive renal failure at an early age. Recent studies in four kindreds showed linkage of a gene for FJHN to the same genomic interval on chromosome 16p11.2, where the gene for the phenotypically similar medullary cystic disease type 2 (MCKD2) has been localised. In this study we performed linkage analysis in additional 15 FJHN families. Linkage of FJHN to 16p11.2 was confirmed in six families, which suggests that, in a large proportion of FJHN kindreds, the disease is likely to be caused by a gene or genes located outside of 16p11.2. Haplotype analysis of the new and previously analysed families provided two non-overlapping critical regions on 16p11.2-FJHN1, delimited by markers D16S499-D16S3036 and FJHN2, delimited by markers D16S412-D16S3116. Considering MCKD2 to be a distinct molecular entity, the analysis suggests that as many as three kidney disease genes may be located in close proximity on 16p11.2. From genomic databases we compiled integrated physical and transcription maps of whole critical genomic region in which 45 known genes and 129 predicted loci have been localised. We selected, analysed and found no pathogenic mutations in seven candidate genes. The linkage and haplotype analysis reported here demonstrates the genetic heterogeneity of FJHN. The report of integrated physical and mostly in-silico predicted transcription maps of the FJHN critical region provides a basis for precise experimental annotation of the current transcript map, which is essential for final identification of the FJHN gene(s).

Equivalence of indapamide SR and enalapril on microalbuminuria reduction in hypertensive patients with type 2 diabetes: the NESTOR Study.

OBJECTIVES: To test whether microalbuminuria in patients with type 2 diabetes and hypertension is primarily dependent on the severity of hypertension, and to compare the effectiveness of two antihypertensive drugs with opposite effects on the renin-angiotensin system [the diuretic, indapamide sustained release (SR), and an angiotensin-converting enzyme inhibitor, enalapril] in reducing microalbuminuria. DESIGN: A multinational, multicentre, controlled, double-blind, double-dummy, randomized, two-parallel-groups study over 1 year. METHODS: After a 4-week placebo run-in period, 570 patients (ages 60.0 +/- 9.9 years, 64% men) with type 2 diabetes, essential hypertension [systolic blood pressure (SBP) 140-180 mmHg, and diastolic blood pressure (DBP) < 110 mmHg], and persistent microalbuminuria (20-200 microg/min) were allocated randomly to groups to receive indapamide SR 1.5 mg (n = 284) or enalapril 10 mg (n = 286) once a day. Amlodipine, atenolol, or both were added, if necessary, to achieve the target blood pressure of 140/85 mmHg. RESULTS: There was a significant reduction in the urinary albumin : creatinine ratio. Mean reductions were 35% [95% confidence interval (CI) 24 to 43] and 39% (95% CI 30 to 47%) in the indapamide SR and enalapril groups, respectively. Equivalence was demonstrated between the two groups [1.08 (95% CI 0.89 to 1.31%); P = 0.01]. The reductions in mean arterial pressure (MAP) were 16.6 +/- 9.0 mmHg for the indapamide SR group and 15.0 +/- 9.1 mmHg for the enalapril group (NS); the reduction in SBP was significantly greater (P = 0.0245 ) with indapamide SR. More than 50% of patients in each group required additional antihypertensive therapy, with no differences between groups. Both treatments were well tolerated. CONCLUSIONS: Indapamide-SR-based therapy is equivalent to enalapril-based therapy in reducing microalbuminuria with effective blood pressure reduction in patients with hypertension and type 2 diabetes.

Physician perception of blood pressure control and treatment behavior in high-risk hypertensive patients: a cross-sectional study.

OBJECTIVE: We examined physician perception of blood pressure control and treatment behavior in patients with previous cardiovascular disease and uncontrolled hypertension as defined by European Guidelines. METHODS: A cross-sectional study was conducted in which 321 primary care physicians throughout Spain consecutively studied 1,614 patients aged ≥18 years who had been diagnosed and treated for hypertension (blood pressure ≥140/90 mmHg), and had suffered a documented cardiovascular event. The mean value of three blood pressure measurements taken using standardized procedures was used for statistical analysis. RESULTS: Mean blood pressure was 143.4/84.9 mmHg, and only 11.6% of these cardiovascular patients were controlled according to 2007 European Guidelines for Hypertension Management target of <130/80 mmHg. In 702 (49.2%) of the 1426 uncontrolled patients, antihypertensive medication was not changed, and in 480 (68.4%) of these cases this was due to the physicians judgment that blood pressure was adequately controlled. In 320 (66.7%) of the latter patients, blood pressure was 130-139/80-89 mmHg. Blood pressure level was the main factor associated (inversely) with no change in treatment due to physician perception of adequate control, irrespective of sociodemographic and clinical factors. CONCLUSIONS: Physicians do not change antihypertensive treatment in many uncontrolled cardiovascular patients because they considered it unnecessary, especially when the BP values are only slightly above the guideline target. It is possible that the guidelines may be correct, but there is also the possibility that the care by the physicians is appropriate since BP <130/80 mmHg is hard to achieve, and recent reviews suggest there is insufficient evidence to support such a low BP target.

Antihypertensive efficacy and safety of olmesartan and ramipril in elderly patients with mild to moderate systolic and diastolic essential hypertension.

OBJECTIVE: To compare the efficacy and safety of olmesartan medoxomil (O) and ramipril (R) in elderly patients with essential arterial hypertension. METHODS: After a 2-week placebo washout, 351 elderly hypertensive patients aged 65-89 years (office sitting diastolic blood pressure, DBP, 90-109 mmHg and office sitting systolic blood pressure, SBP, 140-179 mmHg) were randomized double-blind to 12-week treatment with O 10 mg or R 2.5 mg once daily. After the first 2 and 6 weeks, doses could be doubled in non-normalized (blood pressure <140/90 mmHg for non-diabetic and <130/80 mmHg for diabetic) subjects, up to 40 mg for O and 10 mg for R. Office blood pressures were assessed at randomization, after 2, 6 and 12 weeks of treatment; 24-h ambulatory blood pressure (ABP) was recorded at randomization and after 12 weeks. RESULTS: At week 12, in the intention-to-treat population (170 patients O and 175 R) the rate of normalized subjects was significantly larger in the O group (38.8% vs 26.3% R; p = 0.013). Baseline-adjusted mean sitting office blood pressure reduction at final visit was not significantly greater under O [SBP: 16.6 (95% confidence interval 14.0/19.2) mmHg vs 13.0 (10.4/15.6) mmHg R, p = 0.206; DBP: 11.8 (10.3/13.3) mmHg vs 10.5 (9.0/12.0) mmHg, p = 0.351]. In the subgroup of patients with valid ABP recordings (38 O and 47 R), the reduction in 24-h average blood pressure was significantly (p < 0.01) larger with O [SBP: 8.9 (9.8/8.1) and DBP: 5.7 (6.3/5.1) mmHg] than with R [6.7 (7.9/5.6) and 4.4 (5.1/3.7) mmHg]. The superiority of O was particularly evident in the last 4 h from the dosing interval. The proportion of patients with drug-related adverse events was comparable in the two groups (4.0% O vs 4.5% R), as well as the number of patients discontinuing study drug because of a side-effect (8 O vs 7 R). CONCLUSIONS: In elderly patients with essential arterial hypertension, O provides an effective, prolonged and well tolerated blood pressure control, with significantly better blood pressure normalization than R and represents a useful option among first-line drug treatments of hypertension in this age group.

Hyperuricemia, gout and the metabolic syndrome.

PURPOSE OF REVIEW: The metabolic syndrome is defined by the clustering of a number of cardiovascular risk factors and entails an increased risk for cardiovascular disease and mortality from both cardiovascular disease and all causes. In the present paper, we review the most recent evidence on the association between hyperuricemia, metabolic syndrome, and cardiovascular disease. RECENT FINDINGS: Serum urate is frequently elevated in patients with the metabolic syndrome and increases with the number of components of this condition. Hyperuricemia has been related to decreased renal uric acid excretion, which may be mediated by enhanced proximal tubular sodium reabsorption and hyperinsulinemia. Recent epidemiologic studies have shed some light on the prognosis of hyperuricemia. While hyperuricemia appears to show a benign significance in low cardiovascular risk individuals, it clearly increases cardiovascular mortality in patients at high cardiovascular disease risk. SUMMARY: Clinicians should be aware of the presence of metabolic syndrome in patients with hyperuricemia or gout in order to control its components (high blood pressure, obesity, etc.) and hence reduce the risk for cardiovascular disease. Long-term, randomized interventional clinical trials are needed to test the hypothesis that urate-lowering therapy can reduce cardiovascular risk in these patients.

Clinical profile of eprosartan.

Angiotensin II (AII) receptor blockers offer an alternative means of blocking the renin-angiotensin-aldosterone system (RAAS) to angiotensin converting enzyme (ACE) inhibitors. Being highly selective for the AII receptor subtype AT(1), AII receptor blockers may avoid side-effects associated with ACE inhibitor treatment, such as cough. Eprosartan is a non-biphenyl, non-tetrazole competitive blocker that is chemically distinct from other AII receptor blockers, which may account for differences in its pharmacological properties. It induces dual blockade of AT(1) receptors both presynaptically and postsynaptically, reducing sympathetic nerve activity to a significantly greater degree than other AT(1) receptor blockers. At the recommended dose of 600 mg once daily, eprosartan effectively lowers blood pressure (BP) in hypertensive patients to a similar degree as seen with other AII receptor blockers and ACE inhibitors. However, a greater proportion of patients achieved adequate BP control compared with enalapril. When eprosartan is given in combination with hydrochlorothiazide (HCTZ), it provides a significantly greater BP reduction compared with eprosartan alone. Eprosartan has a side-effect profile that is similar to placebo and to other AII receptor blockers, but is better than that of enalapril because it lacks the propensity to cause dry cough. Eprosartan is not metabolized by the cytochrome P450 enzyme system, and so has no interaction with drugs that affect this system. Eprosartan completely reverses renal vasoconstriction induced by AII and may, therefore, have further applications in situations where stimulation of the RAAS is a problem. In summary, eprosartan, alone or in combination with HCTZ, provides an effective and well-tolerated approach to lowering BP in patients with all grades of hypertension. Further development of eprosartan may offer therapeutic opportunities that go far beyond the current recommendations.