Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.     

Detecting Malingered Pain-Related Disability: Classification Accuracy of the Portland Digit Recognition Test

This study used criterion groups validation to determine the classification accuracy of the Portland Digit Recognition Test (PDRT) at a range of cutting scores in chronic pain patients undergoing psychological evaluation ( n = 318), college student simulators ( n = 29), and patients with brain damage ( n = 120). PDRT scores decreased and failure rates increased as a function of greater independent evidence of intentional underperformance. There were no differences between patients classified as malingering and college student simulators. The PDRT detected from 33% to nearly 60% of malingering chronic pain patients, depending on the cutoff used. False positive error rates ranged from 3% to 6%. Scores higher than the original cutoffs may be interpreted as indicating negative response bias in patients with pain, increasing the usefulness and facilitating the clinical application of the PDRT in the detection of malingering in pain.     

Porcine growth hormone: a central metabolic hormone involved in the regulation of adipose tissue growth.

During the past 20 y, much has been learned about how porcine growth hormone (pGH) affects growth and nutrient partitioning in growing pigs. Our contemporary understanding of the biology of pGH has as its roots the seminal studies conducted by Larry Machlin. His studies and many subsequent reports by other investigators have established that treatment of growing pigs with pGH markedly stimulates muscle growth and, concurrently, reduces fat deposition. In growing pigs, maximally effective doses of pGH increase average daily gain as much as 10% to 20%, improve feed efficiency 15% to 30%, decrease adipose tissue mass and lipid accretion rates by as much as 50% to 80%, and concurrently increase protein deposition by 50%. These effects are associated with a decrease in feed intake of approximately 10% to 15%. These responses occur because pGH has a wide array of biological effects that modulate nutrient partitioning between adipose tissue and skeletal muscle. The decrease in adipose tissue growth is due to a reduction in lipogenesis that is the consequence of pGH blunting the effects of many insulin-dependent events. This article provides an overview of some of the biological effects pGH has in adipose tissue and discusses what is known about the underlying mechanisms that account for these effects.     

Hemodynamic assessment of transluminal angioplasty for lower extremity ischemia

Seventy-two patients underwent hemodynamic testing before and after treatment for occlusive disease of their lower extremities. Percutaneous transluminal angioplasty (PTA) was used to treat lesions in 26 iliac segments and produced 23 initially improved ankle or upper thigh indices, two hemodynamic failures, and one technical failure; PTA for 54 femoropopliteal lesions produced initial hemodynamic improvement in 41 cases, three hemodynamic failures, and ten technical failures. Hemodynamic follow-up of the iliac segments showed improvement in 25 (92%) as measured by the systolic pressure index of the ankle; follow-up of the femoropopliteal segments showed continued patency of 41 (65.9%). The authors analyze these hemodynamic data.     

Small-bowel malabsorption and gastrointestinal malignancy

In addition to lymphoma, there is an increased incidence of gastrointestinal carcinoma in patients with malabsorption due to celiac disease. This is frequently manifested by a loss of response to gluten withdrawal. Four such cases are described: one patient had lymphoma and the other three had cancer of the esophagus, jejunum, and pancreas, respectively. The literature indicates that carcinoma of the esophagus and small bowel is particularly common in patients with celiac disease. These findings suggest that celiac disease should be considered a premalignant condition and that such patients should undergo a regular radiographic survey to detect early cancer.     

Evidence of a Strong Association Between Frequency of Self-Monitoring of Blood Glucose and Hemoglobin A1c Levels in T1D Exchange Clinic Registry Participants

OBJECTIVE

Despite substantial evidence of the benefit of frequent self-monitoring of blood glucose (SMBG) in type 1 diabetes, certain insurers limit the number of test strips that they will provide. The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA_1c levels across a wide age range of children and adults.

RESEARCH DESIGN AND METHODS

The analysis included 20,555 participants in the T1D Exchange clinic registry with type 1 diabetes ≥1 year and not using a continuous glucose monitor (11,641 younger than age 18 years and 8,914 18 years old or older). General linear models were used to assess the association between the number of SMBG measurements and HbA_1c levels after adjusting for potential confounding variables.

RESULTS

A higher number of SMBG measurements per day were associated with non-Hispanic white race, insurance coverage, higher household income, and use of an insulin pump for insulin delivery (P < 0.001 for each factor). After adjusting for these factors, a higher number of SMBG measurements per day was strongly associated with a lower HbA_1c level (adjusted P < 0.001), with the association being present in all age-groups and in both insulin pump and injection users.

CONCLUSIONS

There is a strong association between higher SMBG frequency and lower HbA_1c levels. It is important for insurers to consider that reducing restrictions on the number of test strips provided per month may lead to improved glycemic control for some patients with type 1 diabetes.The advent in the 1980s of meters for self-monitoring of blood glucose (SMBG) has had a substantial impact on the management of type 1 diabetes (1). Several studies have demonstrated a strong correlation between frequency of SMBG and glycemic control (2–5). However, acceptance of the value of frequent SMBG has not been universal and many insurers limit the number of test strips that they will provide to four to six strips per day. In the past year, the Washington State Healthcare Authority questioned whether sufficient evidence is available to justify unlimited coverage of SMBG test strips for patients with type 1 diabetes (6).The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA_1c across a wide age range of children and adults, and to evaluate factors associated with the number of SMBG measurements per day.