Recruitment and Retention for a Weight Loss Maintenance Trial Involving Weight Loss Prior to Randomization.

OBJECTIVE: A weight loss maintenance trial involving weight loss prior to randomization is challenging to implement due to the potential for dropout and insufficient weight loss. We examined rates and correlates of non-initiation, dropout, and insufficient weight loss during a weight loss maintenance trial. METHODS: The MAINTAIN trial involved a 16-week weight loss program followed by randomization among participants losing at least 4 kg. Psychosocial measures were administered during a screening visit. Weight was obtained at the first group session and 16 weeks later to determine eligibility for randomization. RESULTS: Of 573 patients who screened as eligible, 69 failed to initiate the weight loss program. In adjusted analyses, failure to initiate was associated with lower age, lack of a support person, and less encouragement for making dietary changes. Among participants who initiated, 200 dropped out, 82 lost insufficient weight, and 222 lost sufficient weight for randomization. Compared to losing sufficient weight, dropping out was associated with younger age and tobacco use, whereas losing insufficient weight was associated with non-White race and controlled motivation for physical activity. CONCLUSIONS: Studies should be conducted to evaluate strategies to maximize recruitment and retention of subgroups that are less likely to initiate and be retained in weight loss maintenance trials.

The relationship between pretreatment dietary composition and weight loss during a randomised trial of different diet approaches.

BACKGROUND: Identifying pretreatment dietary habits that are associated with weight-loss intervention outcomes could help guide individuals' selection of weight-loss approach among competing options. A pretreatment factor that may influence weight-loss outcomes is macronutrient intake. METHODS: Overweight and obese Durham Veterans Affairs outpatients were randomised to a weight-loss intervention with a low-carbohydrate diet (n = 71) or orlistat medication therapy plus a low-fat diet (n = 73). Percentage fat, carbohydrate and protein intake prior to treatment were measured using 4-day food records. Linear mixed-effects models were used to determine whether pretreatment percentage macronutrient intake influenced weight trajectories and weight loss in each weight-loss condition. RESULTS: Participant's mean age was 53 years, baseline body mass index was 39.3 kg m(-2) and 72% were male. A higher pretreatment percentage carbohydrate intake was associated with less rapid initial weight loss (P = 0.02) and less rapid weight regain (P = 0.03) in the low-carbohydrate diet condition but was not associated with weight trajectories in the orlistat plus low-fat diet condition. In both conditions, a higher pretreatment percentage fat intake was associated with more rapid weight regain (P < 0.01). Pretreatment percentage protein intake was not associated with weight trajectories. None of the pretreatment macronutrients were associated with weight loss on study completion in either condition. CONCLUSIONS: Selection of a weight-loss approach on the basis of pretreatment macronutrient intake is unlikely to improve weight outcomes at the end of a 1-year treatment. However, pretreatment macronutrient intake may have implications for tailoring of interventions to slow weight regain after weight loss.

Two diets with different haemoglobin A1c and antiglycaemic medication effects despite similar weight loss in type 2 diabetes.

We analysed participants with type 2 diabetes (n = 46) within a larger weight loss trial (n = 146) who were randomized to 48 weeks of a low-carbohydrate diet (LCD; n = 22) or a low-fat diet + orlistat (LFD + O; n = 24). At baseline, mean body mass index (BMI) was 39.5 kg/m(2) (s.d. 6.5) and haemoglobin A1c (HbA1c) 7.6% (s.d. 1.3). Although the interventions reduced BMI similarly (LCD -2.4 kg/m(2) ; LFD + O -2.7 kg/m(2) , p = 0.7), LCD led to a relative improvement in HbA1c: -0.7% in LCD versus +0.2% in LFD + O [difference -0.8%, 95% confidence interval (CI) = -1.6, -0.02; p = 0.045]. LCD also led to a greater reduction in antiglycaemic medications using a novel medication effect score (MES) based on medication potency and total daily dose; 70.6% of LCD versus 30.4% LFD + O decreased their MES by ≥50% (p = 0.01). Lowering dietary carbohydrate intake demonstrated benefits on glycaemic control beyond its weight loss effects, while at the same time lowering antiglycaemic medication requirements.

Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors.

A systematic review and meta-analysis were carried out to study the effects of low-carbohydrate diet (LCD) on weight loss and cardiovascular risk factors (search performed on PubMed, Cochrane Central Register of Controlled Trials and Scopus databases). A total of 23 reports, corresponding to 17 clinical investigations, were identified as meeting the pre-specified criteria. Meta-analysis carried out on data obtained in 1,141 obese patients, showed the LCD to be associated with significant decreases in body weight (-7.04 kg [95% CI -7.20/-6.88]), body mass index (-2.09 kg m(-2) [95% CI -2.15/-2.04]), abdominal circumference (-5.74 cm [95% CI -6.07/-5.41]), systolic blood pressure (-4.81 mm Hg [95% CI -5.33/-4.29]), diastolic blood pressure (-3.10 mm Hg [95% CI -3.45/-2.74]), plasma triglycerides (-29.71 mg dL(-1) [95% CI -31.99/-27.44]), fasting plasma glucose (-1.05 mg dL(-1) [95% CI -1.67/-0.44]), glycated haemoglobin (-0.21% [95% CI -0.24/-0.18]), plasma insulin (-2.24 micro IU mL(-1) [95% CI -2.65/-1.82]) and plasma C-reactive protein, as well as an increase in high-density lipoprotein cholesterol (1.73 mg dL(-1) [95%CI 1.44/2.01]). Low-density lipoprotein cholesterol and creatinine did not change significantly, whereas limited data exist concerning plasma uric acid. LCD was shown to have favourable effects on body weight and major cardiovascular risk factors; however the effects on long-term health are unknown.

Low HDL predicts differential blood pressure effects from two weight-loss approaches: a secondary analysis of blood pressure from a randomized, clinical weight-loss trial.

Examining predictors of blood-pressure (BP) response to weight-loss diets might provide insight into mechanisms and help guide clinical care. We examined whether certain baseline patient characteristics (e.g. diet, medical history and laboratory tests) predicted BP response to two weight-loss diet approaches that differ in macronutrient content. One hundred and forty-six overweight adult outpatients were randomized to either a low-carbohydrate diet (N = 72) or orlistat plus a low-fat diet (N = 74) for 48 weeks. Predictors of BP reduction were evaluated using a structured approach and random effects regression models. Participants were 56% African-American, 72% male and 53 (±10) years-old. Of the variables considered, low baseline high-density lipoprotein (HDL) predicted greater reduction in BP in those patients who received the low-carbohydrate diet (p = 0.03 for systolic BP; p = 0.03 for diastolic BP and p = 0.02 for mean arterial pressure). A low HDL level may identify patients who will have greater BP improvement on a low-carbohydrate diet.

The relationship between dietary protein intake and blood pressure: results from the PREMIER study.

Observational and clinical studies suggest that high protein intake, particularly protein from plant sources, might reduce blood pressure (BP). To examine the association of dietary protein with BP, we analysed data from PREMIER, an 18-month clinical trial (n=810) that examined the effects of two multi-component lifestyle modifications on BP. We examined the association of protein intake with BP, and in particular the independent relationship of plant and animal protein with BP. Multivariable linear regression analyses were performed with both cross-sectional and longitudinal data. Dietary plant protein was inversely associated with both systolic and diastolic BP in cross-sectional analyses at the 6-month follow-up (P=0.0045 and 0.0096, respectively). Fruit and vegetable intake was also inversely associated with both systolic and diastolic BP cross-sectionally at 6 months (P=0.0003 and 0.0157, respectively). In longitudinal analyses, a high intake of plant protein at 6 months was marginally associated with a reduction of both systolic and diastolic BP from baseline to 6 months only (P=0.0797 and 0.0866, respectively), independent of change in body weight and waist circumference. Furthermore, increased intake of plant protein, and fruits and vegetables was significantly associated with a lower risk of hypertension at 6 but not at 18 months. Results of this study indicate that plant protein had a beneficial effect on BP and was associated with a lower risk of hypertension at 6 months. Our data, in conjunction with other research, suggest that an increased intake of plant protein may be useful as a means to prevent and treat hypertension.

Acid-base analysis of individuals following two weight loss diets.

OBJECTIVE: To examine the effects of low-carbohydrate, ketogenic (LCKD) and low-fat (LFD) diets on acid-base status. DESIGN: Prospective analysis of volunteers from two clinical trials. PARTICIPANTS: Subset of 39 volunteers from a randomized trial comparing the effects of an LCKD with an LFD, and a single-arm trial of an LCKD. SETTING: Outpatient research clinic. INTERVENTION: LCKD (initially <20 g of carbohydrate daily) or LFD (<30% of energy from fat, 500-1000 kcal energy reduction) instruction. MEASUREMENTS: Arterial blood gas analysis, serum chemistries (electrolytes, urea nitrogen/creatinine, glucose, ketone bodies, lactate), anion gap, and urine ketone bodies measured at weeks 0, 2, 8, and 24. RESULTS: Participants had a mean (+/-standard deviation) age of 43.5+/-9.3 years; 28 (72%) were female, 29 (74%) were Caucasian. Using linear mixed-model analysis to examine blood test changes from baseline to 24 weeks, the LFD group experienced a decrease in arterial blood pH from a mean of 7.43 at week 0 to 7.40 at week 24 (P=0.03), and the LCKD group experienced a decrease from 7.42 at week 0 to 7.40 at week 24 (P=0.01). The lowest pH measurements observed were 7.34 in the LFD group and 7.37 in the LCKD group. Although serum bicarbonate appeared to decrease from baseline at weeks 2 and 8 in the LCKD group, the change at 24 weeks was not statistically significant in either diet group, and only four of 131 (two of 92 from the LCKD group) measurements were less than 22 mmol/l. The proportion of participants with elevated urine and serum ketone body levels rose in the LCKD group only, was highest at week 2, and decreased over the subsequent time points. CONCLUSION: In individuals following an LCKD or an LFD, blood pH decreased mildly and the LCKD group experienced a small, transient decrease in serum bicarbonate in conjunction with mild ketosis. This suggests that an LCKD induced a mild compensated metabolic acidosis, but no individual showed evidence of significant metabolic derangement.

Diet therapy for narcolepsy.

The effects of a low-carbohydrate, ketogenic diet (LCKD) on sleepiness and other narcolepsy symptoms were studied. Nine patients with narcolepsy were asked to adhere to the Atkins' diet plan, and their symptoms were assessed using the Narcolepsy Symptom Status Questionnaire (NSSQ). The NSSQ-Total score decreased by 18% from 161.9 to 133.5 (p = 0.0019) over 8 weeks. Patients with narcolepsy experienced modest improvements in daytime sleepiness on an LCKD.

Improvement of gastroesophageal reflux disease after initiation of a low-carbohydrate diet: five brief case reports.

The 5 individuals described in these case reports experienced resolution of GERD symptoms after self-initiation of a low-carbohydrate diet. Their observations suggest that carbohydrate restriction may have contributed to their symptom relief. However, this conclusion is confounded by concurrent reduction of caffeine intake in 3 of the individuals and reduction of acidic and high-osmolal food intake in all of them. Observations from some of these individuals suggest that carbohydrates may be a precipitating factor for GERD symptoms and that other classic exacerbating foods such as coffee and fat may be less pertinent when a low-carbohydrate diet is followed. However, these conclusions are preliminary. These findings primarily suggest that prospective research should be performed on the effect of low-carbohydrate diets on GERD symptoms. Trials that control for all of the confounders mentioned above and that contain objective endpoints are needed to further investigate these issues.

Patient satisfaction in resident and attending ambulatory care clinics.

OBJECTIVE: To measure and compare patient satisfaction with care in resident and attending physician internal medicine ambulatory care clinics. DESIGN: A cross-sectional survey using a questionnaire derived from the Visit-Specific Satisfaction Questionnaire (VSQ) and Patient Satisfaction Index (PSI) distributed from March 1998 to May 1998. SETTING: Four clinics based at a university teaching hospital and the associated Veterans' Affairs (VA) hospital. PARTICIPANTS: Two hundred eighty-eight patients of 76 resident and 25 attending physicians. RESULTS: Patients of resident physicians at the university site were more likely to be African American, male, have lower socioeconomic status and have lower physical and mental health scores on the Short Form-12 than patients of university attendings. Patients of resident and attending physicians at the VA site were similar. In multivariate analyses, patients of university attending physicians were more likely to be highly satisfied than patients of university residents on the VSQ-Physician (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.6 to 7.8) and the PSI-Physician (OR, 10.1; 95% CI, 3.7 to 27.4) summary scores. Differences were not seen on the summary scores at the VA site. Two individual items displayed significant differences between residents and attendings at both sites: "personal manner (courtesy, respect, sensitivity, friendliness) of the doctor" (P

Condom use by adolescents.

The use of condoms as part of the prevention of unintended pregnancies and sexually transmitted diseases (STDs) in adolescents is evaluated in this policy statement. Sexual activity and pregnancies decreased slightly among adolescents in the 1990s, reversing trends that were present in the 1970s and 1980s, while condom use among adolescents increased significantly. These trends likely reflect initial success of primary and secondary prevention messages aimed at adolescents. Rates of acquisition of STDs and human immunodeficiency virus (HIV) among adolescents remain unacceptably high, highlighting the need for continued prevention efforts and reflecting the fact that improved condom use can decrease, but never eliminate, the risk of acquisition of STDs and HIV as well as unintended pregnancies. While many condom education and availability programs have been shown to have modest effects on condom use, there is no evidence that these programs contribute to increased sexual activity among adolescents. These trends highlight the progress that has been made and the large amount that still needs to be accomplished.

Antibody response of 18 month old children 1 month and 18 months following Haemophilus influenzae type b vaccine administered singly or with DTP vaccine.

Seventy-six children (aged 17-19 months) received 10 micrograms of Haemophilus influenzae type b polyribosyl-ribitol phosphate (PRP) vaccine, diluted with either phosphate-buffered saline (PBS) or diphtheria-tetanus-pertussis (DTP) vaccine, in a single-blind randomized trial. There were few side effects when PRP was administered alone. Before vaccination 37 of 76 children (49%) had non-protective antibody levels (less than 0.15 micrograms/mL); 26 of these 37 (70%) achieved antibody levels of greater than 0.15 micrograms/mL 1 month after vaccination. Before vaccination 16 of 76 (21%) had antibody levels of greater than 1.0 micrograms/mL; 1 month after vaccination 39 of 76 children (51%) achieved levels of greater than 1.0 micrograms/mL. Of 12 infants who had antibody levels less than 0.15 micrograms/mL 1 month after immunization, 10 had protective levels 18 months later. Administration of PRP mixed with DTP did not affect antibody response to PRP. The potential use and limitations of PRP vaccine are discussed.

Considerations for the physician who treats adolescents in the office.

The purpose of an interview is to obtain information that will assist the physician in evaluating a patient's problem, and that will allow him or her to make appropriate recommendations toward solution of the problem. The major effort by the physician should be to provide the proper setting, and to be an interested, understanding listener. An opportunity to talk to someone who will listen in a caring way may be all that the usually uncommunicative adolescent needs. The primary care physician can obtain the knowledge, arrange for the necessary time, and develop the caring, sensitive attitude to talk with and counsel patients about many subjects, including sensitive ones. Sometimes, however, regardless of how hard one tries, the teenage adolescent patient will be reluctant to discuss his or her concerns. This should not be considered a failure, and the physician should not become discouraged. One should recognize the difficulty the adolescent is having and offer to be available in the near future when the adolescent patient may be ready to express his or her concerns.

Community resources for adolescents.

The optimal approach to adolescent health care frequently requires that physicians and other health care providers work with community support systems to develop a multidisciplinary diagnostic and therapeutic team. Just as the primary care providers must be aware of the capabilities of specialist consultants to whom patients are referred for complicated medical problems, they must also develop a working knowledge of the community services available for the specific needs of adolescents with behavioral and developmental problems. This article provides some practical guidelines toward this goal.

Evaluation of behavior and development training for pediatric residents.

The evaluation of a behavior and development training program that was integrated into a general pediatric training residency is reported. Thirty-two residents who participated in the program were evaluated over one year on measures designed to assess residents' opinions about the relevance of behavior and development concepts, residents' perceptions of their own competence in behavior and development knowledge and skills, supervisors' ratings of residents' general clinical performance, and residents' attitudes about 10 specific illnesses. Results suggest that residents perceive a high relevance for psychosocial concepts and an increasing competence with these concepts after training. Establishing rapport with patients emerged as an important variable in supervisors' ratings of resident performance and in residents' self-ratings of competence. Attitudes were initially negative toward the more behavioral and psychophysiological disease entities but showed some positive change over the year. These results and their implications are discussed.