Chronic kidney disease and cardiovascular disease in the Medicare population

BACKGROUND: The extent of diabetes, chronic kidney disease (CKD), and cardiovascular disease (CVD) in the Medicare population is relatively unknown. Also unknown is the effect of these diseases on patient survival before end-stage renal disease (ESRD). METHODS: Prevalent cohorts of Medicare enrollees from 1996 to 2000 were assessed for diabetes and CKD, presence of CVD, and probability of death versus ESRD in the follow-up period. Hospitalization rates and, in diabetics, lipid testing and glycemic control monitoring were also assessed. RESULTS: The prevalence of diabetes in the Medicare population increased at 4.4% per year, reaching 18.9% in the 1999-2000 cohort. Approximately 726,000 elderly Medicare enrollees carry a diagnosis code for CKD. Those with CKD are 5 to 10 times more likely to die before reaching ESRD than the non-CKD group. In CKD patients, CVD is twice as common and advances at twice the rate. Cardiovascular disease advances at a similarly higher rate in CKD patients who die and those who survive to ESRD. Heart failure hospitalizations are 5 times greater in CKD patients and only 30% less than those in dialysis patients. Only half of the CKD patients with diabetes who advance to ESRD had a lipid or glycosylated hemoglobin test done in the year before or after dialysis initiation. CONCLUSION: Diabetes, the leading cause of ESRD, is increasing in the general Medicare population at 4.4% per year. Cardiovascular disease is common, progresses at twice the rate, is associated with death before ESRD, and patients receive suboptimal risk factor monitoring. Active identification and treatment of CKD patients is needed.     

Athletes with exercise-associated fatigue have abnormally short muscle DNA telomeres

INTRODUCTION/PURPOSE: Although the beneficial health effects of regular moderate exercise are well established, there is substantial evidence that the heavy training and racing carried out by endurance athletes can cause skeletal muscle damage. This damage is repaired by satellite cells that can undergo a finite number of cell divisions. In this study, we have compared a marker of skeletal muscle regeneration of athletes with exercise-associated chronic fatigue, a condition labeled the "fatigued athlete myopathic syndrome" (FAMS), with healthy asymptomatic age- and mileage-matched control endurance athletes. METHODS: Muscle biopsies of the vastus lateralis were obtained from 13 patients diagnosed with FAMS and from 13 healthy control subjects. DNA was extracted from the muscle samples and their telomeric restriction fragment (TRF) or telomere lengths were measured by Southern blot analysis. RESULTS: All 13 symptomatic athletes reported a progressive decline in athletic performance, decreased ability to tolerate high mileage training, and excessive muscular fatigue during exercise. The minimum value of TRF lengths (4.0 +/- 1.8 kb) measured on the DNA from vastus lateralis biopsies from these athletes were significantly shorter than those from 13 age- and mileage-matched control athletes (5.4 +/- 0.6 kb, P < 0.05). Three of the FAMS patients had extremely short telomeres (1.0 +/- 0.3 kb). The minimum TRF lengths of the remaining 10 symptomatic athletes (4.9 +/- 0.5 kb, P < 0.05) were also significantly shorter that those of the control athletes. CONCLUSION: These findings suggest that skeletal muscle from symptomatic athletes with FAMS show extensive regeneration which most probably results from more frequent bouts of satellite cell proliferation in response to recurrent training- and racing-induced muscle injury.     

Third ventriculostomy for internal hydrocephalus complicated by unrecognized subdural hygroma and hematoma: a case report of a patient treated by Dr. Walter Dandy

The authors review the case of a patient treated by Dr. Walter Dandy. When the patient was a young child he underwent two right transtemporal third ventriculostomies during which he sustained an unrecognized contralateral subdural hygroma and a chronic subdural hematoma with a mild infantile hemiparesis. He was able to complete high school, albeit at a slower pace than usual. As an adult he held several limited employment positions, lived at home for several decades, and was later cared for at a nursing home for a short time. The patient died when he was 66 years of age.     

Risperidone treatment of motor restlessness following anoxic brain injury

Primary objective: This paper examined the use of an atypical neuroleptic medication, risperidone, in reducing the excessive motor activity of an adolescent with an anoxic brain injury following cardiac arrest from a lightning strike. Lower extremity restlessness caused the patient to develop skin breakdown and interfered with healing of existing burns.

Research design: Single-blind, placebo-controlled single-subject experimental design.

Experimental intervention: Escalating doses of risperidone up to 1 mg and in combination with methylphenidate (10 mg) and amantidine (100 mg).

Main outcomes and results: The patient demonstrated a reduction in restlessness in response to the use of risperidone, which permitted wound healing. The addition of methlphenidate to risperidone led to a slight increase in attention to task.

Conclusions: The use of the atypical neuroleptic medication, risperidone, may be considered as part of the armamentarium available to physicians treating restlessness in severe brain injuries.     

Safety of gadolinium contrast angiography in patients with chronic renal insufficiency

OBJECTIVE: To prevent iodinated contrast medium-induced nephrotoxicity, gadolinium has been used increasingly for magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA) to visualize arterial anatomy in patients undergoing vascular surgery who are considered at high risk because of chronic renal insufficiency. We assessed the safety of gadolinium-based contrast medium as a substitute for iodinated contrast medium-enhanced examinations. We determined the incidence of gadolinium-induced nephrotoxicity in a clinical setting and searched for contributing risk factors.Patients and methods In a single-center retrospective study from December 1999 to January 2001, 218 inpatients underwent MRA and 42 inpatients underwent DSA, with gadolinium as the sole contrast agent. Patient comorbid conditions, indications for vascular imaging, contrast dose, urine output, baseline and post-procedure serum creatinine concentration (SCr), and outcome were recorded for all patients in whom gadolinium-induced renal failure developed. RESULTS: Of 260 patients who received gadolinium-based contrast agents, at a dose of 0.25 mmol/kg or more, 195 patients (75%) had pre-test baseline chronic renal insufficiency. In 7 of 195 patients (3.5%) acute renal failure developed after gadolinium-based contrast medium administration, for MRA (n = 153) in 3 patients (1.9%) and DSA (n = 42) in 4 patients (9.5%). Average baseline SCr in the 195 patients with chronic renal insufficiency was 38.2 +/- 1.6 mL/min/1.73 m(2), and in the 7 patients in whom acute renal failure developed, baseline SCr was 32.5 +/- 7.8 mL/min/1.73 m(2) (P =.33). Respective intravenous and intra-arterial gadolinium doses in these 7 patients ranged from 0.31 to 0.41 mmol/kg for MRA and 0.27 to 0.42 mmol/kg for DSA. Acute renal failure did not develop in any of 65 patients with normal baseline SCr. CONCLUSION: Despite reports of negligible nephrotoxicity, rarely gadolinium-based contrast agents can cause acute renal failure in patients with underlying chronic renal insufficiency. Estimation of creatinine clearance alone does not enable prediction of which patients are likely to have acute renal failure. Patients at high-risk should be identified, and prophylactic measures should be taken to reduce the risk for nephrotoxicity.     

Hypersensitive knockin mouse strains identify receptors and pathways for nicotine action

Two series of knockin mouse strains have been constructed with point mutations that result in hypersensitive neuronal nicotinic acetylcholine receptors containing alpha 4- or alpha 7-subunits. The full expression of the stronger alleles produces neonatal excitotoxic lethality; however, mice with attenuated expression or milder alleles are viable, and display a range of hypersensitive responses to nicotine. To date, measurements have been made on nicotine-induced seizures, Straub tail, hypothermia, antinociception, electroencephalograms and cellular electrophysiological responses. These strains are helping to define the occurrence of these important receptor subtypes, and their role in the acute and chronic actions of nicotine. The hypersensitive strains may be useful for the development of nicotinic drug therapy.     

Protein-energy malnutrition and involuntary weight loss: nutritional and pharmacological strategies to enhance wound healing

Clinically significant involuntary weight loss (IWL) is defined as a loss of 4.5 kg or > 5% of the usual body weight over a period of 6 - 12 months, especially when progressive. Weight loss of > 10% of normal body weight is considered to represent protein-energy malnutrition (PEM). Despite progress in our understanding of the aetiology and pathophysiology of IWL and PEM, these conditions remain frequent and serious problems in several high-risk populations in both acute and long-term care facilities. In patients with IWL and PEM, nonhealing wounds signal a catabolic process that requires prompt nutritional intervention. Aggressive nutritional therapy that provides adequate protein, calories and micronutrients, combined with an anabolic agent such as oxandrolone, may provide the most optimal environment for restoration of lean body mass and body weight and in turn, promote wound healing. More research, however, is needed to define optimal nutritional and anabolic therapies for these patients given the associated high morbidity and cost of care.     

Does deliberation make a difference? Results from a citizens panel study of health goals priority setting

How to involve the public in setting health and health care priorities is a constant challenge for health system decisions. Policy maker interest in involving the public in increasingly complex and value-laden priority setting processes has led to the use of deliberative public involvement methods designed to promote discussion and debate among participants with the objective of obtaining more informed and consensual views. These methods have not been evaluated rigorously using controlled designs with pre- and post-test measurements. We examined, using a controlled design, the effects of introducing different opportunities for deliberation into a process for obtaining public input into a community health goals priority setting process. Our findings indicate that deliberation does make a difference to participant views. As more deliberation is introduced, participant views may be more amenable to change. Deliberation also offers the potential for views to become more rather than less entrenched. While we are beginning to understand the difference deliberation makes to participant views, we are still at an early stage in understanding the process through which these differences come about and what difference deliberation makes to broader outcomes such as civic competence, civic engagement and health policy decisions.     

Evaluation of factors determining the precision of body composition measurements by air displacement plethysmography

OBJECTIVES: To investigate methodological precision of air displacement plethysmography for assessment of body composition in a heterogenous sample of adults. DESIGN: Accuracy of volume measurements by air displacement plethysmography (ADP) for a range of known volumes was ascertained. Repeated measurements of body volume, lung volume, and derived body composition using the BODPOD measurement system were performed. Influence of surface area estimation on ADP measurement was investigated as a possible source of variation. SETTING: Clinical Nutrition Laboratory, School of Health & Sports Science, University of North London, London, UK. SUBJECTS: One hundred and two healthy subjects (57 women, 45 men) who ranged in age between 16 and 55 y and in BMI (kg/m(2)) between 17.8 and 41.9. STUDY DESIGN: Cross-sectional study of healthy adults for comparison with previous studies. Repeat measurements of raw body volume, lung volume and % body fat (BF) by ADP were all performed on the same day. RESULTS: From the range of known volumes a marked increase in the CV and a significantly greater measurement error were found at volumes below 40 l (P=0.04). Repeat measurements of raw body volume in human subjects resulted in a technical error equivalent to 0.8% BF. There was no significant difference found between measured and predicted lung volume and the 95% confidence interval for difference was only 0.3% BF. Repeat measurements of lung volume in our subset resulted in a technical error equivalent to 0.5% BF. Although body surface area estimation only accounted for variation in % BF of 0.1%, the extent of variation appeared to be governed by leanness (P<0.001). CONCLUSIONS: Although ADP retains excellent precision, in practice, repeat measurements of ADP should be performed whenever possible to allow for erroneous volume measurement within one procedure. Protocols for ADP measurement should be created with an awareness of those factors, which may affect measurements. SPONSORSHIPS: This study was supported by the University of North London Diversity & Development Fund.