Dose-response Clinical Trial Research Articles

Effect of Sinetrol® Xpur on metabolic health and adiposity by interactions with gut microbiota: a randomized, open label, dose–response clinical trial

BackgroundSinetrol® Xpur is a polyphenolic ingredient rich in citrus flavonoids that has shown weight loss effects in previous studies. The dose dependent nature, gut microbial actions of this product has not been explored previously, thus presented in this study.MethodsIn this open label study, we evaluated the effect of Sinetrol® Xpur supplementation on healthy but overweight/obese adults (20–50 yrs) for 16 weeks. Participants (n = 20) were randomly allocated to a high dose group (HD, 1800 mg/day) or low dose group (LD, 900 mg/day) of the product for 16 weeks. Fat composition, gut microbial composition, were evaluated using MRI and 16S rDNA sequencing respectively at week 1 and 16.ResultsWe observed HDL, HbA1C, LDL and leptin improved significantly over 16 weeks, irrespective of the dosage. There was a trend for decrease in visceral adipose tissue (VAT), BMI over time and body weight displayed a trend for dose dependent decrease. Eubacterium xylanophilum, Ruminococcacea UCG-004 genus which increased in HD and LD respectively were negatively associated to VAT. Both doses increased butyrate producers such as Eubacterium ruminantium and Ruminococcaceae NK4A214 genus.ConclusionsOverall chronic supplementation of Sinetrol® Xpur, irrespective of their dose improved HDL, HbA1c, LDL and leptin and tended to decrease visceral adipose tissue via changes in gut microbiota.Trial registration number NCT03823196.

Cocoa Consumption Decreases Oxidative Stress, Proinflammatory Mediators and Lipid Peroxidation in Healthy Subjects: A Randomized Placebo-Controlled Dose-Response Clinical Trial.

Cocoa flavonoids have been described to reduce the cardiovascular risk. Nevertheless, the involved mechanisms should be clarified and the dose-effect relation has never been evaluated. To investigate the dose-dependent effects of cocoa flavonoids on markers of endothelial and platelet activation and oxidative stress. According to a randomized, double-blind, controlled, cross-over design, 20 healthy nonsmokers were assigned to receive either five treatments with daily intake of 10g cocoa (0, 80, 200, 500 and 800mg cocoa flavonoids/day) in five periods lasting 1 week each. Compared with flavonoid-free cocoa control, cocoa reduced sICAM-1 mean values [from 1190.2 to 1123.0; 906.3; 741.7 and 625.6 pg/mL (p = 0.0198 and p = 0.0016, for 500 and 800mg respectively], sCD40L mean values [from 218.8 to 210.2; 165.5; 134.5 and 128.4 pg/mL (p = 0.023 and p = 0.013, for 500 and 800mg respectively] and 8-isoprostanes F2 mean values [from 4703.9 to 4670.7; 2000.1; 2098.4 and 2052.3 pg/mL (p = 0.025; p = 0.034 and p = 0.029, for 200, 500 and 800mg respectively)]. In our study we observed that short-term cocoa consumption improved proinflammatory mediators, lipid peroxidation and oxidative stress with a significant effect for higher dosages of flavonoids. Our findings suggest cocoa might be a valid tool for dietary intervention in prevention of atherosclerosis.

Beneficial Role of Calcium in Premenstrual Syndrome: A Systematic Review of Current Literature.

Since premenstrual syndrome (PMS) is one of the most common and debilitating disorders in women, risk factor modification is an urgent health priority. Therefore, this systematic review aimed to summarize and discuss the outcomes of observational and interventional studies in humans regarding the relationship between Calcium and PMS. PubMed, Scopus, ISI web of sciences and Google scholar were searched up to January 2019 to identify relevant studies. The Newcastle-Ottawa and Jadad scales were used for quality assessment. A total of 14 studies (8 interventional and 6 observational) met our inclusion criteria. Majority of the studies showed that not only serum calcium levels are lower in PMS subjects, but also calcium supplementation could significantly improve the incidence of PMS and its related symptoms. This systematic review suggests a beneficial role for calcium in PMS subjects. However, in order to draw a firm link between calcium and PMS, further dose-response clinical trials with larger sample size and better methodological design are warranted.

Toward a Scientific Nutritional Supplement Combination for Prostatism and Erectile Dysfunction I: From Known Pharmacology to Clinical Testing.

Prostatism and erectile dysfunction (ED) are highly prevalent and closely comorbid. Prescription treatments are limitingly expensive but robust in mechanisms of action (MoA). Nutritional supplements (NS) are low-cost but inadequately supported by evidence. Do any NS use robust MoA? Could their efficacy be amplified via dosing, concentration of active principles, and/or use in combination? The goal is to develop an effective NS for prostatism and ED using the MoA of prescription treatments. Literature reviews were conducted on dietary supplements for prostatism or ED and MoA of relevant drugs. The most promising NS employing these MoA were chosen. A pilot study of a prototype combination was conducted. A protocol was created for an adequate dose-response trial to test the NS combination in men with ED and prostatism. The main measures were response rates, International Prostate Symptom Score, and International Index of Erectile Function. For drugs, the MoAs best proven for prostatism and ED were nitric oxide augmentation, mild androgen inhibition, and anti-inflammatory effects. The following NS best simulate these MoA and are best supported for efficacy; for prostatism: beta sitosterol; for ED: panax ginseng, arginine, and citrulline. Pilot clinical data provided support. A plan for a formal dose-response clinical trial was approved by a central institutional review board. NS using effective MoA might suffice for prostatism and ED. Pilot testing of a combination NS with the best-supported MoA supported further development. A dose-response trial should be conducted using adequate doses of L-citrulline, beta-sitosterol, ginseng, and vitamin D3.

Randomized, four-arm, dose-response clinical trial to optimize resistance exercise training for older adults with age-related muscle atrophy

PurposeThe myriad consequences of age-related muscle atrophy include reduced muscular strength, power, and mobility; increased risk of falls, disability, and metabolic disease; and compromised immune function. At its root, aging muscle atrophy results from a loss of myofibers and atrophy of the remaining type II myofibers. The purpose of this trial (NCT02442479) was to titrate the dose of resistance training (RT) in older adults in an effort to maximize muscle regrowth and gains in muscle function. MethodsA randomized, four-arm efficacy trial in which four, distinct exercise prescriptions varying in intensity, frequency, and contraction mode/rate were evaluated: (1) high-resistance concentric-eccentric training (H) 3d/week (HHH); (2) H training 2d/week (HH); (3) 3d/week mixed model consisting of H training 2d/week separated by 1 bout of low-resistance, high-velocity, concentric only (L) training (HLH); and (4) 2d/week mixed model consisting of H training 1d/week and L training 1d/week (HL). Sixty-four randomized subjects (65.5±3.6y) completed the trial. All participants completed the same 4weeks of pre-training consisting of 3d/week followed by 30weeks of randomized RT. ResultsThe HLH prescription maximized gains in thigh muscle mass (TMM, primary outcome) and total body lean mass. HLH also showed the greatest gains in knee extension maximum isometric strength, and reduced cardiorespiratory demand during steady-state walking. HHH was the only prescription that led to increased muscle expression of pro-inflammatory cytokine receptors and this was associated with a lesser gain in TMM and total body lean mass compared to HLH. The HL prescription induced minimal muscle regrowth and generally lesser gains in muscle performance vs. the other prescriptions. Major conclusionsThe HLH prescription offers distinct advantages over the other doses, while the HL program is subpar. Although limited by a relatively small sample size, we conclude from this randomized dose-response trial that older adults benefit greatly from 2d/week high-intensity RT, and may further benefit from inserting an additional weekly bout of low-load, explosive RT. Trial registrationClinicalTrials.govNCT02442479

Bayesian penalized log-likelihood ratio approach for dose response clinical trial studies

ABSTRACTIn literature, there are a few unified approaches to test proof of concept and estimate a target dose, including the multiple comparison procedure using modeling approach, and the permutation approach proposed by Klingenberg. We discuss and compare the operating characteristics of these unified approaches and further develop an alternative approach in a Bayesian framework based on the posterior distribution of a penalized log-likelihood ratio test statistic. Our Bayesian approach is much more flexible to handle linear or nonlinear dose–response relationships and is more efficient than the permutation approach. The operating characteristics of our Bayesian approach are comparable to and sometimes better than both approaches in a wide range of dose–response relationships. It yields credible intervals as well as predictive distribution for the response rate at a specific dose level for the target dose estimation. Our Bayesian approach can be easily extended to continuous, categorical, and time-to-event responses. We illustrate the performance of our proposed method with extensive simulations and Phase II clinical trial data examples.

Abstract 1758: Circulating insulin-like growth factors: Correlates and responses to calcium supplementation in colorectal adenoma patients

Abstract Insulin-like growth factor 1 (IGF-1) and its binding proteins are an important part of the IGF/growth hormone axis needed for normal growth and organ function. IGF-1 signaling has also been implicated in tumorigenesis with higher circulating levels of IGF-1 and the molar ratio of IGF-1 to IGF binding protein 3 (IGFBP-3) being directly associated with colorectal, breast, and prostate cancers, as well as with colorectal adenomas. IGF binding protein 2 (IGFBP-2) also appears to be overexpressed in colorectal and lung cancers and leukemias. Limited evidence suggests that various dietary and lifestyle factors may influence circulating levels of IGF-1, IGFBP-2, and IGFBP-3. Among these factors, calcium has been statistically significantly associated with IGF-1, IGFBP-2, and IGFBP-3, but its effects on them have not been tested in a clinical trial. To investigate the effects of supplemental calcium (1.0 or 2.0 g/day) on serum levels of IGF-1, IGFBP-2, and IGFBP-3, we analyzed samples from a randomized, double-blinded, placebo-controlled, dose-response clinical trial of patients with previous sporadic, colorectal adenoma. We also investigated associations of various risk factors with the growth factors at baseline. IGF-1 was measured using an enzyme-linked immunosorbent assay, and IGFBP-2 and IGFBP-3 were measured using quantitative Western ligand blot assays. We found no appreciable effects of calcium over the 4-month treatment period on IGF-1, IGFBP-2, and IGFBP-3. At baseline, lower levels of IGF-1 and IGFBP-3 were associated with being female (P = 0.02 and 0.01, respectively) or older (P = 0.02 and 0.02, respectively); the IGF-1/IGFBP-3 molar ratio was inversely associated with body mass index (BMI) (P = 0.04); and IGFBP-2 was directly associated with age (P = 0.002) but inversely associated with BMI (P < 0.0001). We calculated residuals of non-fat milk intake as a novel method of examining the non-calcium, non-fat component of milk, modeled after the energy adjustment residual method. These residuals were inversely associated with IGFBP-2 (P = 0.05) and directly associated with the IGF-1/IGFBP-3 molar ratio (P = 0.11). Overall, our results do not support that calcium supplementation can modulate circulating levels of IGF-1, IGFBP-2, or IGFBP-3 among patients with previous colorectal adenoma. However, our findings do suggest potential associations of these growth factors with established risk factors for colorectal cancer (age [inversely associated with IGF-1 and IGFBP-3, directly associated with IGFBP-2] and adiposity [inversely associated with IGFBP-2 and the IGF-1/IGFBP-3 molar ratio]). Finally, our results provide new evidence of potential associations of IGF-1, IGFBP-2, and IGFBP-3 with milk intake independent of its calcium and fat content. Citation Format: Caroline Um, Veronika Fedirko, Christine Höflich, W Dana Flanders, Roberd M. Bostick. Circulating insulin-like growth factors: Correlates and responses to calcium supplementation in colorectal adenoma patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1758.

A comparison of three doses of omeprazole in the treatment of equine gastric ulcer syndrome: A blinded, randomised, dose-response clinical trial.

A previous study demonstrated that a dose effect between 1.6 and 4.0 mg/kg bwt of omeprazole per os s.i.d. is present in the treatment of equine gastric ulceration. In the same study, healing of glandular ulceration appeared inferior to healing of squamous ulceration. However, several limitations were recognised in that study and further investigation is warranted. To further investigate the presence of a dose relationship in the treatment of gastric ulceration under conditions that may favour omeprazole efficacy such as administration prior to exercise and after a brief fast, and potential differences between the response of squamous and glandular ulceration to omeprazole therapy. A blinded, randomised, dose-response clinical trial. Sixty Thoroughbred racehorses with grade ≥2/4 squamous and/or glandular ulceration were identified by gastroscopy. Horses were randomly assigned to receive either 1.0, 2.0 or 4.0 mg/kg bwt of enteric coated omeprazole per os s.i.d. 1-4 h prior to exercise. Gastroscopy was repeated at approximately 28 days. The lower doses studied (1.0 and 2.0 mg/kg bwt) were noninferior to the reference dose (4.0 mg/kg bwt) in the treatment of squamous ulceration. Healing was greater in squamous ulceration than glandular ulceration (86% vs. 14%; P<0.0001). Improvement in ulcer grade was more likely in squamous lesions than glandular lesions (96% vs. 34%; P<0.0001). Worsening of the glandular ulcer grade was observed in 36% of horses. The results of this study suggest that, under the conditions studied, where omeprazole is administered before exercise and following a brief fast, doses of omeprazole as low as 1 mg/kg bwt per os s.i.d. may be as effective as higher doses. The proportion of glandular ulceration that heals with 28 days of omeprazole therapy is less than that of squamous ulceration.

Urinary Isoxanthohumol Is a Specific and Accurate Biomarker of Beer Consumptionce1–3

Biomarkers of food consumption are a powerful tool to obtain more objective measurements of dietary exposure and to monitor compliance in clinical trials. In this study, we evaluated the effectiveness of urinary isoxanthohumol (IX) excretion as an accurate biomarker of beer consumption. A dose-response clinical trial, a randomized, crossover clinical trial, and a cohort study were performed. In the dose-response trial, 41 young volunteers (males and females, aged 28 ± 3 y) consumed different doses of beer at night and a spot urine sample was collected the following morning. In the clinical trial, 33 males with high cardiovascular risk (aged 61 ± 7 y) randomly were administered 30 g of ethanol/d as gin or beer, or an equivalent amount of polyphenols as nonalcoholic beer for 4 wk. Additionally, a subsample of 46 volunteers from the PREDIMED (Prevenciόn con Dieta Mediterránea) study (males and females, aged 63 ± 5 y) was also evaluated. Prenylflavonoids were quantified in urine samples by liquid chromatography coupled to mass spectrometry. IX urinary recovery increased linearly with the size of the beer dose in male volunteers. A significant increase in IX excretion (4.0 ± 1.6μg/g creatinine) was found after consumption of beer and nonalcoholic beer for 4 wk (P < 0.001). Receiver operating characteristic curves showed that IX is able to discriminate between beer consumers and abstainers with a sensitivity of 67% and specificity of 100% (positive predictive value = 70%, negative predictive value = 100% in real-life conditions). IX in urine samples was found to be a specific and accurate biomarker of beer consumption and may be a powerful tool in epidemiologic studies. This trial was registered at the International Standard Randomized Controlled Trial registry as ISRCTN72996101 (study 1), ISRCTN95345245 (study 2), and ISRCTN35739639 (study 3).

A new gel formulation of topical cysteamine for the treatment of corneal cystine crystals in cystinosis: The Cystadrops OCT-1 study

ObjectiveTo establish the safety and efficacy of a new gel formulation of cysteamine hydrochloride (CH) eye drops, for the treatment of corneal complications of nephropathic cystinosis. DesignOpen label dose response clinical trial. ParticipantsEight patients with infantile nephropathic cystinosis including 4 children, 3 adolescents, and 1 adult (mean age at inclusion, 12.1±4.6years) treated with CH 0.1% eye drops. InterventionPatients were treated, in both eyes, with the control CH 0.1% eye drop formulation on average 4 times daily for one month and then switched to Cystadrops® at the same dose frequency. Based on clinical ocular findings, the dose regimen was adapted at D30 and D90 in order to decrease the frequency of instillation. After D90, this dose frequency was maintained, except in cases of crystal density worsening. Patients had a follow-up visit every 6months during 48months. Main outcome measuresSafety assessment consisted of adverse event and serious adverse event monitoring and recording at each visit. For the efficacy study, the primary endpoint was the corneal cystine crystal density measured with an in vivo confocal microscopy (IVCM) score. ResultsAll patients completed the study. During the 4-year study period, neither serious adverse events nor significant adverse events related to the study drug were reported. After switching to Cystadrops®, the IVCM total score decreased from baseline to D90 by a mean of 28.6±17.5% (p<0.001). From D90 to M48, the IVCM total score remained stable and significantly decreased as compared to that at D1 despite a reduced dose regimen from D90. At M48, the mean IVCM total score was 8.13±4.15, decreased by a mean 29.9±26.29% from D1 (p=0.001), with a reduced number of instillations compared to that at D1. The IVCM total score and photophobia were significantly correlated (p=0.04). ConclusionThis study provides evidence that Cystadrops® gel is superior to the CH 0.1% formulation in terms of efficacy and has a good safety profile over a long follow-up period.

Discharge-based QMRA for estimation of public health risks from exposure to stormwater-borne pathogens in recreational waters in the United States

This study is the first to report a quantitative microbial risk assessment (QMRA) on pathogens detected in stormwater discharges-of-concern, rather than relying on pathogen measurements in receiving waters. The pathogen concentrations include seven “Reference Pathogens” identified by the U.S. EPA: Cryptosporidium, Giardia, Salmonella, Norovirus, Rotavirus, Enterovirus, and Adenovirus. Data were collected from 12 sites representative of seven discharge types (including residential, commercial/industrial runoff, agricultural runoff, combined sewer overflows, and forested land), mainly during wet weather conditions during which times human health risks can be substantially elevated. The risks calculated herein therefore generally apply to short-term conditions (during and just after rainfall events) and so the results can be used by water managers to potentially inform the public, even for waters that comply with current criteria (based as they are on a 30-day mean risk). Using an example waterbody and mixed source, pathogen concentrations were used in QMRA models to generate risk profiles for primary and secondary water contact (or inhalation) by adults and children. A number of critical assumptions and considerations around the QMRA analysis are highlighted, particularly the harmonization of the pathogen concentrations measured in discharges during this project with those measured (using different methods) during the published dose–response clinical trials. Norovirus was the most dominant predicted health risk, though further research on its dose–response for illness (cf. infection) is needed. Even if the example mixed-source concentrations of pathogens had been reduced 30 times (by inactivation and mixing), the predicted swimming-associated illness rates – largely driven by Norovirus infections – can still be appreciable. Rotavirus generally induced the second-highest incidence of risk among the tested pathogens while risks for the other Reference Pathogens (Giardia, Cryptosporidium, Adenovirus, Enterovirus and Salmonella) were considerably lower. Secondary contact or inhalation resulted in considerable reductions in risk compared to primary contact. Measurements of Norovirus and careful incorporation of its concentrations into risk models (harmonization) should be a critical consideration for future QMRA efforts. The discharge-based QMRA approach presented herein is particularly relevant to cases where pathogens cannot be reliably detected in receiving waters with detection limits relevant to human health effects.

Fitting Emax models to clinical trial dose–response data

We consider fitting Emax models to the primary endpoint for a parallel group dose–response clinical trial. Such models can be difficult to fit using Maximum Likelihood if the data give little information about the maximum possible response. Consequently, we consider alternative models that can be derived as limiting cases, which can usually be fitted. Furthermore we propose two model selection procedures for choosing between the different models. These model selection procedures are compared with two model selection procedures which have previously been used. In a simulation study we find that the model selection procedure that performs best depends on the underlying true situation. One of the new model selection procedures gives what may be regarded as the most robust of the procedures.

A Dunnett–Bonferroni‐based parallel gatekeeping procedure for dose–response clinical trials with multiple endpoints

This paper proposes a Dunnett-Bonferroni-based parallel gatekeeping procedure in a setting of dose-response clinical trials with multiple endpoints. It follows the Dunnett-based parallel gatekeeping strategy of Dmitrienko et al. (Pharm. Stat. 2006; 5:19-28), but differs in the calculation of the critical values. The implementation of the Dunnett-based parallel gatekeeping procedure relies on assumptions difficult to justify in typical clinical trials, namely (a) that the joint distribution of the test statistics from different endpoints can be approximated by a multivariate-t distribution and (b) that the true correlation between multiple endpoints can be well estimated using observed data. The proposed Dunnett-Bonferroni-based parallel gatekeeping procedure relaxes the preceding assumptions by splitting type I error rate among families using the Bonferroni inequality. While it is potentially less powerful than a Dunnett-based procedure when both procedures are applicable, the power loss is very minimal. Our proposed method avoids assumptions that might be challenged by regulatory agencies and does so with virtually no cost. Moreover, in most cases this method is easier to implement compared with the Dunnett-based procedure.

Fallback Tests in Dose-Response Clinical Trials

This article introduces a general testing procedure for performing dose-control comparisons in dose-response trials with one or more endpoints. The procedure (termed multi-stage fallback procedure) is an extension of the fallback test proposed by Wiens (2003). The multi-stage fallback procedure features a simple stepwise form and improves the power of dose-control tests at higher doses by taking into account the ordering of the doses. It also serves as an efficient tool for handling multiplicity caused by multiple endpoints. It is shown in this article that the multi-stage fallback procedure can be formulated as a closed testing procedure and thus controls the Type I error rate with respect to multiple dose-control comparisons as well as multiple endpoints. The proposed testing method is illustrated using examples from dose-response clinical trials with single and multiple endpoints.

Guest Editors' Note for the Special Issue on “Design and Analysis of Dose-Response Clinical Trials”

Guest Editors' Note for the Special Issue on “Design and Analysis of Dose-Response Clinical Trials”

Gatekeeping procedures in dose–response clinical trials based on the Dunnett test

This paper discusses multiple testing procedures in dose-response clinical trials with primary and secondary endpoints. A general gatekeeping framework for constructing multiple tests is proposed, which extends the Dunnett test [Journal of the American Statistical Association 1955; 50: 1096-1121] and Bonferroni-based gatekeeping tests developed by Dmitrienko et al. [Statistics in Medicine 2003; 22:2387-2400]. The proposed procedure accounts for the hierarchical structure of the testing problem; for example, it restricts testing of secondary endpoints to the doses for which the primary endpoint is significant. The multiple testing approach is illustrated using a dose-response clinical trial in patients with diabetes. Monte-Carlo simulations demonstrate that the proposed procedure provides a power advantage over the Bonferroni gatekeeping procedure. The power gain generally increases with increasing correlation among the endpoints, especially when all primary dose-control comparisons are significant.

Commentary: Renal Effects of Cyclooxygenase-2-Selective Inhibitors

Since the discovery of the first nonselective nonsteroidal anti-inflammatory drug (NSAID), aspirin, in 1897, physicians have been managing NSAID-induced adverse events, including gastrointestinal ulceration and bleeding and renal effects (e.g., renal dysfunction, changes in blood pressure, peripheral edema, and hyperkalemia). The cyclooxygenase (COX)-2-specific inhibitors (coxibs) were developed as a safer alternative to NSAIDs in patients at risk for developing gastrointestinal toxicity. However, through inhibition of constitutive COX-2 in the kidneys, the production of prostaglandins, which are responsible for regulating electrolyte and water balance and vascular tone, may be decreased, leading to such renal effects as sodium and potassium retention, peripheral edema, and acute reversible renal dysfunction.

Sample Size for Linear and Quadratic Terms in a Dose-Response Relationship

Tables for sample size determination in parallel group dose-response clinical trials analyzed with second degree equations are presented in this paper. They were obtained by simulations and provide sample sizes to detect, with different power values, single degree of freedom F tests for a linear component (indicating a trend across doses) and a quadratic component (usually indicating a plateau, less frequently a nonmonotonic relationship or a steep change in slope).In addition to a sample size for a linear pattern (response proportional to log dose), one nonmonotonic example and different patterns with plateaus are available. Selection of a pattern depends on previous pharmacological information. Sample sizes to detect quadratic components are usually larger than those for the linear component, except in the nonmonotonic case (rare but important to detect). Practical considerations for choosing the patterns in a given situation are described.

Effect of megestrol acetate on quality of life in a dose-response trial in women with advanced breast cancer. The Cancer and Leukemia Group B.

The impact of the side effects of megestrol acetate on the quality of life of noncachectic women with advanced breast cancer was studied in a dose-response clinical trial of the Cancer and Leukemia Group B (CALGB 8741). Side effects of appetite increase and weight gain at higher doses were predicted to have a negative effect on quality of life. Stage IV breast cancer patients were randomized to receive either 160, 800, or 1,600 mg/d of megestrol acetate. Quality of life was assessed in 131 patients at trial entry and at 1 and 3 months while on treatment, by telephone interview, using the following measures: the Functional Living Index-Cancer (FLIC), Rand Functional Limitations Scale, Rand Mental Health Inventory (MHI), the Body Image Subscale, and linear analog scales of drug side effects. At 3 months, women treated with 160 mg/d reported less severe side effects (P < .0005), better physical functioning (FLS, P < .0005), less psychologic distress (MHI, P = .008), and an improvement in overall quality of life (FLIC, P = .003) from the time of study entry as compared with those treated with 1,600 mg/d. Patients who received the 800-mg/d dose fell between the low- and high-dose arms in reported intensity of drug side effects, but responded similarly to those in the 160-mg/d group in terms of physical functioning, psychologic distress, and overall quality of life. Unless additional follow-up data demonstrate a survival advantage at higher doses, the 160-mg/d dose is optimal, achieving maximal treatment effect with the fewest side effects and better quality of life.

Women Walking for Health and Fitness

We studied whether the quantity and quality of walking necessary to decrease the risk of cardiovascular disease among women differed substantially from that required to improve cardiorespiratory fitness. A randomized, controlled, dose-response clinical trial with a follow-up of 24 weeks. A private, nonprofit biomedical research facility. One hundred two sedentary premenopausal women, 20 to 40 years of age, were randomized to one of four treatment groups; 59 completed the study (16 aerobic walkers [8.0-km/h group], 12 brisk walkers [6.4-km/h group], 18 strollers [4.8-km/h group], and 13 sedentary controls). Eighty-one percent were white, 17% black, and 2% Hispanic. Intervention groups walked 4.8 km per day, 5 days per week at 8.0 km/h, 6.4 km/h, or 4.8 km/h on a tartan-surfaced, 1.6-km track for 24 weeks. Fitness (determined by maximal oxygen uptake) and cardiovascular risk factors (determined by resting blood pressure and serum lipid and lipoprotein levels). As compared with controls, maximal oxygen uptake increased significantly (P less than .0001) and in a dose-response manner (aerobic walkers greater than brisk walkers greater than strollers). In contrast, high-density lipoprotein cholesterol concentrations were not dose related and increased significantly (P less than .05) and to the same extent among women who experienced considerable improvements in their physical fitness (8.0-km/h group, +0.08 mmol/L) and those who had only minimal improvements in fitness (4.8-km/h group, +0.08 mmol/L). High-density lipoprotein cholesterol also increased among the 6.4-km/h group, but did not attain statistical significance (+0.06 mmol/L; P = .06). Dietary patterns revealed no significant differences among groups. Thus, we conclude that vigorous exercise is not necessary for women to obtain meaningful improvements in their lipoprotein profile. Walking at intensities that do not have a major impact on cardiorespiratory fitness may nonetheless produce equally favorable changes in the cardiovascular risk profile.