Long-term weight loss and changes in blood pressure: results of the Trials of Hypertension Prevention, phase II.

BACKGROUND: Weight loss appears to be an effective method for primary prevention of hypertension. However, the long-term effects of weight loss on blood pressure have not been extensively studied. OBJECTIVE: To present detailed results from the weight loss arm of Trials of Hypertension Prevention (TOHP) II. DESIGN: Multicenter, randomized dinical trial testing the efficacy of lifestyle interventions for reducing blood pressure over 3 to 4 years. Participants in TOHP II were randomly assigned to one of four groups. This report focuses only on participants assigned to the weight loss (n = 595) and usual care control (n = 596) groups. PATIENTS: Men and women 30 to 54 years of age who had nonmedicated diastolic blood pressure of 83 to 89 mm Hg and systolic blood pressure less than 140 mm Hg and were 110% to 165% of their ideal body weight at baseline. INTERVENTION: The weight loss intervention included a 3-year program of group meetings and individual counseling focused on dietary change, physical activity, and social support MEASUREMENTS: Weight and blood pressure data were collected every 6 months by staff who were blinded to treatment assignment RESULTS: Mean weight change from baseline in the intervention group was -4.4 kg at 6 months, -2.0 kg at 18 months, and -0.2 kg at 36 months. Mean weight change in the control group at the same time points was 0.1, 0.7, and 1.8 kg. Blood pressure was significantly lower in the intervention group than in the control group at 6, 18, and 36 months. The risk ratio for hypertension in the intervention group was 0.58 (95% CI, 0.36 to 0.94) at 6 months, 0.78 (CI, 0.62 to 1.00) at 18 months, and 0.81 (CI, 0.70 to 0.95) at 36 months. In subgroup analyses, intervention participants who lost at least 4.5 kg at 6 months and maintained this weight reduction for the next 30 months had the greatest reduction in blood pressure and a relative risk for hypertension of 0.35 (CI, 0.20 to 0.59). CONCLUSIONS: Clinically significant long-term reductions in blood pressure and reduced risk for hypertension can be achieved with even modest weight loss.

Achievement and safety of a low blood pressure goal in chronic renal disease. The Modification of Diet in Renal Disease Study Group.

The Modification of Diet in Renal Disease Study showed a beneficial effect of a lower-than-usual blood pressure (BP) goal on the progression of renal disease in patients with proteinuria. The purpose of the present analyses was to examine the achieved BP, baseline characteristics that helped or hindered achievement of the BP goals, and safety of the BP interventions. Five hundred eighty-five patients with baseline glomerular filtration rate between 13 and 55 mL/min per 1.73 m2 (0.22 to 0.92 mL/s per 1.73 m2) were randomly assigned to either a usual or low BP goal (mean arterial pressure < or = 107 or < or = 92 mm Hg, respectively). Few patients had a history of cardiovascular disease. All antihypertensive agents were permitted, but angiotensin-converting enzyme inhibitors (with or without diuretics) followed by calcium channel blockers were preferred. The mean (+/- SD) of the mean arterial pressures during follow-up in the low and usual BP groups was 93.0 +/- 7.3 and 97.7 +/- 7.7 mm Hg, respectively. Follow-up BP was significantly higher in subgroups of patients with preexisting hypertension, baseline mean arterial pressure > 92 mm Hg, a diagnosis of polycystic kidney disease or glomerular diseases, baseline urinary protein excretion > 1 g/d, age > or = 61 years, and black race. The frequency of medication changes and incidence of symptoms of low BP were greater in the low BP group, but there were no significant differences between BP groups in stop points, hospitalizations, or death. When data from both groups were combined, each 1-mm Hg increase in follow-up systolic BP was associated with a 1.35-times greater risk of hospitalization for cardiovascular or cerebrovascular disease. Lower BP than usually recommended for the prevention of cardiovascular disease is achievable by several medication regimens without serious adverse effects in patients with chronic renal disease without cardiovascular disease. For patients with urinary protein excretion > 1 g/d, target BP should be a mean arterial pressure of < or = 92 mm Hg, equivalent to 125/75 mm Hg.

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.

Nutrition intervention program of the Modification of Diet in Renal Disease Study: a self-management approach.

OBJECTIVE: To characterize the Modification of Diet in Renal Disease (MDRD) Study nutrition intervention program by determining the frequency of intervention strategies used by the dietitians and the usefulness of program components as rated by participants. DESIGN: Dietitians recorded which of 32 intervention strategies they used at each monthly visit. Participants rated the usefulness of 19 program components. SUBJECTS: 840 adults with renal insufficiency. INTERVENTION: Participants were assigned randomly to usual-, low-, or very-low-protein diet groups. Each eating pattern also specified a phosphorus intake goal. Each participant met monthly with a dietitian for an average of 26 months. STATISTICAL ANALYSES: Analyses of variance and chi 2 analyses. RESULTS: Dietitians used the following intervention strategies most often in all groups: providing feedback based on self-monitoring and/or food records, reviewing adherence or biochemistry data, providing low-protein foods, and reviewing graphs of adherence progress. In general, the dietitians used feedback, modeling, and support strategies more often, and knowledge and skills strategies less often, with participants who had to make the greatest reductions in protein intake and those with more advanced disease. In all groups, the dietitians' use of knowledge and skills, feedback, and modeling strategies decreased over time (P < .001), whereas use of support strategies was maintained. The type and frequency of intervention strategies used by dietitians and the usefulness ratings of participants did not vary by educational level of the participant. Both self-monitoring and dietitian support were rated as "very useful" by 88% of the participants. CONCLUSIONS: Three features were central to the MDRD Study nutrition intervention program: feedback, particularly from self-monitoring and from measures of adherence; modeling, particularly by providing low-protein food products; and dietitian support. We recommend the self-management approach.

Factors associated with adherence to the dietary protein intervention in the Modification of Diet in Renal Disease Study.

OBJECTIVE: To determine the characteristics and behaviors associated with adherence to dietary protein interventions among participants with chronic renal disease in the Modification of Diet in Renal Disease (MDRD) Study. DESIGN: Participants were categorized as consistent adherers or nonadherers on the basis of urinary urea nitrogen excretion and dietary protein intake data from self-reports. Psychosocial and behavioral factors were compared between groups. SUBJECTS: Subgroups of consistently adherent and non-adherent participants in the MDRD Study. SETTING: 15 clinical centers in the United States. INTERVENTION: In the nutrition intervention program, participants were assigned randomly to a usual-, low-, or very-low-protein diet group. Each eating pattern also specified a phosphorus goal. STATISTICAL ANALYSIS: Analysis of variance. RESULT: Psychosocial factors significantly related to adherence included participant knowledge, attitude, support, satisfaction, and self-perception of success. Behavioral strategies including participant self-monitoring of protein intake and the provision of feedback by the dietitian were also significantly related to adherence. APPLICATION: Nutrition interventions for patients with renal disease should focus on psychosocial factors and behavioral approaches. Such approaches can be successfully incorporated into treatment programs and will assist the dietitian in promoting adherence to usual-, low-, and very-low-protein eating patterns.

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.

A long-term nutrition intervention experience: lipid responses and dietary adherence patterns in the Multiple Risk Factor Intervention Trial.

Nutrition counselors in the Multiple Risk Factor Intervention Trial (MRFIT) were able to help middle-aged men who were at high risk for coronary heart disease change their dietary habits, maintain those changes over time, and decrease their serum cholesterol levels. Most of a 7.5% mean serum cholesterol reduction achieved after 6 years of nutrition intervention occurred during the first year of the trial and was thereafter sustained. Total cholesterol and low-density lipoprotein cholesterol fraction decreases indicated improvement in terms of coronary heart disease risk. The food record rating, a numerical, semi-objective adherence technique that assesses a 3-day food record with respect to lipid-lowering potential, was used throughout the trial to measure adherence to recommended food patterns. Participants with lower food record rating scores, which indicate better adherence, demonstrated greater reductions in serum total cholesterol, plasma total cholesterol, and low-density lipoprotein fraction cholesterol determinations on a group basis. Subjective evaluations of the suitability of home and working environments, evidence of deviation from the MRFIT food patterns, and overall nutrition program motivation also showed that as ratings in each category became more favorable, lower food record rating scores and greater blood lipid reductions were consistently observed. The subgroup of participants who were non-smokers and not hypertensive demonstrated greater lipid responses and better dietary adherence. Continued smoking and antihypertensive medications appeared to adversely influence dietary adherence and/or lipid reductions. The MRFIT experience, however, demonstrated for the first time that dietary changes and blood lipid reductions can be achieved after the initial intervention effect, despite a continued emphasis on high blood pressure management and smoking cessation.

The measurement of sodium and potassium intake.

Single- vs multiple-day food records were compared for estimates of intake for sodium, potassium, and calories; and the correspondence was assessed between sodium and potassium intake and 24-h urinary excretion. Fifty-five middle-aged adults, participating in a prerandomization assessment for a nutritional/behavioral intervention program on blood pressure completed a six-day food record and a 24-h urine collection. The group average for sodium, potassium, and calories obtained from one-day food records proved to be as good an estimate of the six-day average as did values from multiple day records. Similarly the one-day food record proved a good estimate of the mean 24-h urinary values for sodium and potassium. If properly collected and analyzed, a one-day food record is a good estimate of a population's intake of sodium and potassium while multiple days of recording are necessary to characterize individual intake.