Examining social influence on participation and outcomes among a network of behavioral weight-loss intervention enrollees

Research suggests that social networks, social support, and social influence are associated with weight trajectories among treatment- and non-treatment-seeking individuals. This study examined the impact of having a social contact who participated in the same group behavioral weight-control intervention in the absence of specific social support training on women engaged in a weight-loss program. Participants (n = 92; 100% female; 54% black; mean age: 46 ± 10 years; mean BMI: 38 ± 6) were grouped based upon whether or not they reported a social contact enrolled previously/concurrently in our behavioral weight-control studies. Primary outcomes were 6-month weight change and treatment adherence (session attendance and self-monitoring). Half of the participants (53%) indicated that they had a social contact; black women were more likely to report a social contact than white women (67.3% versus 39.5%; P < 0.01). Among participants with a social contact, 67% reported at least one contact as instrumental in the decision to enroll in the program. Those with a contact lost more weight (5.9 versus 3.7 kg; P = 0.04), attended more group sessions (74% versus 54%; P < 0.01), and submitted more self-monitoring journals (69% versus 54%; P = 0.01) than those without a contact. Participants' weight change was inversely associated with social contacts' weight change (P = 0.04). There was no association between participant and contact's group attendance or self-monitoring. Social networks may be a promising vehicle for recruiting and engaging women in a behavioral weight-loss program, particularly black women. The role of a natural social contact deserves further investigation.

Efficacy and safety of cetirizine therapy in perennial allergic rhinitis

A double-blind, placebo-controlled trial was undertaken to assess the safety and efficacy of once daily cetirizine in alleviating the symptoms of perennial allergic rhinitis. Subjects were adults with perennial allergic rhinitis, characterized by nasal congestion, postnasal discharge, sneezing, rhinorrhea, nasal itching, lacrimation, ocular itching, and itching of the roof of the mouth, and a total pretreatment symptom severity score of greater than or equal to 8. Patients were randomized to treatment with 10 mg cetirizine, 20 mg cetirizine, or placebo for 4 weeks. Efficacy was assessed in 215 patients and safety in 216. Cetirizine in once daily dosages of 10 or 20 mg proved to be effective in relieving the overall symptoms of perennial allergic rhinitis and particularly postnasal discharge and sneezing. The 10-mg dose afforded optimal symptomatic relief, and the 20-mg dose provided little or no additional benefit. Cetirizine was well tolerated, and the frequency of somnolence was not significantly greater in patients receiving this drug than in those given placebo.

Effect of food on nifedipine pharmacokinetics

The effect of food on the bioavailability of nifedipine (Procardia), 10 mg capsules, was studied. Each of 15 male volunteers received a single oral 10 mg dose with 120 ml water under three conditions: fasting, after a low-fat (high-carbohydrate) meal, and after a high-fat meal. An open, three-way Latin-square design was employed with a 4-day washout period between administrations. Serial blood samples were collected just before the dose (0 hour) and from 0 to 8 hours after administration. Nifedipine assays were performed by GLC/electron capture detection. Diet did not appreciably alter the AUC from 0 to 8 hours, the AUC from 0 to infinity, or the elimination half-life. The time to peak (tmax) and peak concentrations (Cmax) were significantly altered by food. The mean Cmax values for fasting, low-fat, and high-fat meals were 78.9, 42.2, and 58.7 ng/ml, respectively. The mean tmax values for these three conditions were 0.97, 1.89, and 1.07 hours, respectively. The results indicate that food, in particular a low-fat (high-carbohydrate) meal, slows the rate but does not alter the extent of nifedipine absorption. Insofar as certain side effects (e.g., flushing and headache) may be related to the high peak plasma levels associated with rapid absorption, administration with meals might serve to reduce the incidence of such effects. Clinical trials would be necessary to confirm this possibility. For the majority of patients on routine maintenance therapeutic regimens, nifedipine capsules may be administered without regard to food intake.

Relationship between transcutaneous oxygen tension, ankle blood pressure, and clinical outcome of vascular surgery in diabetic and nondiabetic patients

We measured ankle systolic blood pressure (ABP) and limb transcutaneous oxygen tension (TcPO2) before and after 53 vascular procedures performed to relieve limb-threatening ischemia. We compared changes in ABP and TcPO2 and also compared these measurements of limb hemodynamics with the clinical outcome of the vascular procedures. For the procedures performed on patients without diabetes, both ABP and TcPO2 registered similar changes after surgery. Furthermore, those nondiabetic patients who had a postoperative ABP greater than 75 mm Hg or TcPO2 greater than 20 mm Hg showed resolution of the clinical symptoms within 60 days after surgery. All patients falling below these levels underwent a subsequent limb amputation. The results differed somewhat for procedures performed on patients with diabetes. First, a number of diabetic patients showed high ABP in conjunction with low TcPO2. We attribute these observations to the high incidence in diabetic patients of calcific medial stenosis leading to artificially elevated ABP measurements. Second, the clinical outcome among diabetic patients was uncorrelated with the postoperative ABP and was poorly correlated with postoperative TcPO2. Those diabetic patients with postoperative TcPO2 below 20 mm Hg showed unfavorable clinical outcomes, but many patients with postoperative TcPO2 greater than 20 mm Hg and postoperative ABP greater than 75 mm Hg also showed unfavorable clinical outcome (slow healing of ulcers, persistence of rest pain, and/or an amputation on the limb). These data suggest that among our patients with diabetes, simple relief of limb ischemia was not sufficient to result in a trouble-free clinical course. We conclude that TcPO2 is a useful replacement or adjunct to ABP measurements for evaluating the hemodynamic outcome of vascular surgery. Our results also suggest that it is extremely important to evaluate the outcome of such surgeries separately in patients with and without diabetes.

Factors relating to the sensory acuity of limbs with peripheral vascular insufficiency

We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin.

A rapid, universal TI-59 model-independent pharmacokinetic analysis program based on statistical moment theory

A model-independent program for pharmacokinetic analyses based on statistical moment theory is presented and demonstrated. The program uses an inexpensive and portable TI-59; a PC-100A printer adds convenience but is optional. The program may be used in analysis of blood, serum, or plasma concentration vs. time curves originating from iv, im, po, sl, or sc administration. Drug input can be zero or first order; both single-dose and multiple-dose steady-state conditions can be evaluated. A comparison between results generated using moment analysis and traditional two-compartment nonlinear regression showed excellent agreement.