Weight cycling and high-density lipoprotein cholesterol in women: evidence of an adverse effect: a report from the NHLBI-sponsored WISE study. Women's Ischemia Syndrome Evaluation Study Group

OBJECTIVES

We undertook an analysis of weight cycling, coronary risk factors and angiographic coronary artery disease (CAD) in women.

BACKGROUND

The effect of weight cycling on cardiovascular mortality and morbidity is controversial, and the impact of weight cycling on cardiovascular risk factors is unclear.

METHODS

This is a cross-sectional population study of 485 women with coronary risk factors undergoing coronary angiography for evaluation of suspected myocardial ischemia enrolled in the Women's Ischemia Syndrome Evaluation (WISE). Reported lifetime weight cycling-defined as voluntary weight loss of at least 10 lbs at least 3 times--coronary risk factors including core laboratory determined blood lipoproteins and CAD, as determined by a core angiographic laboratory, are the main outcome measures.

RESULTS

Overall, 27% of women reported weight cycling--19% cycled 10 to 19 lbs, 6% cycled 20 to 49 lbs, and 2% cycled 50+ lbs. Reported weight cycling was associated with 7% lower high-density lipoprotein cholesterol (HDL-C) levels in women (p = 0.01). The HDL-C effect was directly related to the amount of weight cycled with women who lost > or = 50 lbs/cycle having HDL-C levels 27% lower than noncyclers (p = 0.0025). This finding was independent of other HDL-C modulators, including estrogen status, physical activity level, alcohol intake, body mass index, diabetes, beta-blocker use, cigarette smoking and race. Weight cycling was not associated with an increased prevalence of CAD in this population.

CONCLUSIONS

Weight cycling is associated with lower HDL-C in women of a magnitude that is known to be associated with an increased risk of cardiac events as demonstrated in prior clinical trials.

Quality of lipid and lipoprotein measurements in community laboratories

OBJECTIVE

To determine the reliability of cholesterol and lipoprotein measurements conducted in local community laboratories.

METHODS

Standardized duplicate serum aliquots at three concentrations (low, intermediate, and high) of total cholesterol, triglycerides, and high-density lipoprotein cholesterol were sent to 21 laboratories used by the physicians participating in the Cholesterol-Lowering Intervention Program. Results obtained from the laboratories were compared with values obtained from the Centers for Disease Control and Prevention-standardized Heinz Lipid Laboratory and with the means of the entire sample.

RESULTS

The mean coefficient of variation (CV) was 1.3% or less for all three levels of total cholesterol, which demonstrates a high degree of precision. Accuracy was also high; over 80% of all laboratories were within 5% of the Heinz Laboratory low reference value, and all were within the 5% range for the medium and high samples. The CVs for triglycerides (< 2.3%) and high-density lipoprotein cholesterol (< 2.2%) were similar to that for total cholesterol, but up to 56% and 61% of the values fell outside the Heinz reference range for high-density lipoprotein cholesterol (intermediate concentration) and triglycerides (low concentration), respectively. As the Heinz Laboratory has a negative 2.7% bias versus the Centers for Disease Control and Prevention for total cholesterol and high-density lipoprotein cholesterol measurements, a higher percentage of laboratories fell outside the Centers for Disease Control and Prevention range. For medium and high total cholesterol samples, 16% of the laboratories were outside the 5% Centers for Disease Control and Prevention range, and the value was 58% for the low total cholesterol sample. For high-density lipoprotein cholesterol the percentages were 61%, 56%, and 39% for the low, medium, and high samples, respectively.

CONCLUSIONS

These data suggest that according to the standards set by the National Cholesterol Education Program Laboratory Standardization Panel, reliability of total cholesterol measurements in local laboratories is high. Lower levels of accuracy were noted for triglycerides and high-density lipoprotein cholesterol measurements.

Cholesterol-lowering intervention program. Effect of the step I diet in community office practices

BACKGROUND

A randomized study was conducted to test the feasibility of cholesterol lowering in physician office practices using the National Cholesterol Education Program Adult Treatment Panel 1 guidelines.

METHODS

Twenty-two physician practices in phase 1 and 23 in phase 2 were recruited from communities in Western Pennsylvania and West Virginia. These physicians treated a total of 450 adults in phase 1 (190 men and 260 women) and 480 adults in phase 2 (184 men and 296 women) with hypercholesterolemia. Three models (Usual Care [phase 1], Office Assisted [phase 2], and Nutrition Center [phase 2]) for implementing the National Cholesterol Education Program Adult Treatment Panel 1 guidelines were tested over an 18-month period. The baseline serum cholesterol levels were as follows: 6.51 mmol/L (252 mg/dL) in the Usual Care Model; 6.80 mmol/L (262 mg/dL) in the Office Assisted Model; and 6.96 mmol/L (269 mg/dL) in the Nutrition Center Model.

RESULTS

In the patients who were not taking lipid-lowering medication, the mean cholesterol response was significantly different between the 3 models (P < .01). Serum cholesterol levels declined by 0.14 mmol/L (5.4 mg/dL) in the Usual Care Model; by 0.31 mmol/L (12 mg/dL) in the Office Assisted Model; and by 0.54 mmol/L (20.9 mg/dL) in the Nutrition Center Model. Two factors-length of time to follow-up measurement and change in weight-were independently related to cholesterol response across all models. African Americans demonstrated a significantly smaller response than whites in the Usual Care Model, while men demonstrated greater declines in serum cholesterol levels than women in the Office Assisted Model. Patient satisfaction was very favorable in both enhanced conditions; however, those treated in the the Nutrition Center Model were more satisfied (P < .05) with program components.

CONCLUSIONS

The impact of nutrition intervention delivered through physician practices on serum cholesterol levels is less than clinically desirable, and new approaches with more aggressive therapy should be tested and implemented.

Registered dietitian time requirements in the Modification of Diet in Renal Disease Study

OBJECTIVE

To assess time expended by registered dietitians to conduct clinical and research activities during the Modification of Diet in Renal Disease (MDRD) Study.

DESIGN

Two randomized, controlled clinical trials among persons with diminished levels of renal function using a factorial design to evaluate effects of dietary protein restriction and blood pressure control on progression of renal disease. In study A, subjects with moderate renal insufficiency were randomly assigned to a diet of usual protein (1.30 g/kg per day) or low protein (0.58 g/kg per day) and to either a usual or low blood pressure level. Study B involved subjects with advanced renal insufficiency who were randomly assigned to the low-protein diet or a very-low-protein prescription (0.28 g/kg per day) with a ketoacid-amino acid supplement (0.28 g/kg per day) and to either the usual or low blood pressure level. A time-log form designed by MDRD Study dietitians was completed for each participant at 36 monthly follow-up visits.

SETTING

Fifteen clinical centers throughout the continental United States.

SUBJECTS

Eight hundred forty adults aged 18 to 70 years with chronic renal diseases participated in the MDRD Study--585 in study A and 255 in study B.

STATISTICAL ANALYSES

One-way analyses of variance and t tests were used to evaluate significant time requirement differences by diet groups, diagnosis, and sociodemographics.

RESULTS

Mean total time for all participant visits declined from 183 +/- 1 minutes per visit during months 1 through 4 to 116 +/- 41 minutes per visit during months 25 through 36. Significantly more dietitian time was required for participants consuming the low-protein and very-low-protein diets than for those consuming the usual-protein diet. Age, gender, race, marital status, and renal diagnosis did not influence time requirements. A significant inverse association between education level and dietitian time was apparent.

APPLICATIONS

The MDRD Study time-log data should be useful when determining staffing patterns for nutrition management in clinical and research settings.

Evaluating the efficacy of the National Cholesterol Education Program adult treatment guidelines: cholesterol lowering intervention program

BACKGROUND

A cross-sectional analysis was conducted to test the feasibility of the National Cholesterol Education Program Adult Treatment Panel I Guidelines (ATPI) in physician office practices.

METHODS

Twenty-two physician practices in communities from western Pennsylvania and West Virginia were recruited. Using a patient tracking system, 9,171 patients were assessed for cholesterol screening and treatment by their physicians according to the ATPI guidelines.

RESULTS

Cholesterol screening was ordered for 1,698 patients or 19% of the population visiting the physician offices. The reasons for not screening included the patient was already under therapy (2,371), screened within the past 5 years (1,714), or acutely ill at the time of the visit (1,691). The frequency of patient refusal for screening was low (444). However, the majority of patient diagnoses were based on a single lipid measurement, and only 817 or 56% of patients evaluated had lipoprotein measures obtained prior to treatment. Follow-up measurement was not performed according to the ATPI schedule, and the magnitude of cholesterol response was inversely related to time to first follow-up measurement.

CONCLUSIONS

Many patients in these physician practices had initial cholesterol screening. However, repeat measurements as recommended for initial evaluation were not performed routinely, nor were most patients followed within the recommended 3-month time period. This lack of follow-up is detrimental to effective, long-term patient management since the magnitude of the cholesterol response is related to time of the first follow-up measurement.