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.

Molecular scanning analysis of hepatocyte nuclear factor 1alpha (TCF1) gene in typical familial type 2 diabetes in African Americans.

Type 2 diabetes mellitus (T2DM) is strongly inherited, but the major genes for this disease have been elusive. In contrast, early-onset, autosomal-dominant diabetes results from at least 5 loci, of which hepatocyte nuclear factor 1a (HNF1alpha or TCF1) is the most common cause. Mutations in HNF1alpha also cause later-onset diabetes in some Caucasian populations, but the role of these mutations has not been tested in African American populations. We used a variety of screening methods, including both single-strand conformation polymorphism (SSCP) analysis and dideoxy fingerprint analysis, to search for mutations in 51 African American subjects with onset of diabetes before age 50 years. Potential mutations were confirmed by direct sequencing. We identified 21 different variants, of which 11 were unique to African Americans. Four mutations either altered the amino acid sequence (Gly52Ala and Gly574Ser) or were close to a splice site (intron 1 and intron 10). A 5-nucleotide insertion in intron 1 was present in both diabetic members of a small family, but Gly52Ala, Gly574Ser, and the intron 10 mutation did not segregate with diabetes. Gly574Ser was present in 2 large families and 5% of controls, all of which appeared to share the same common HNF1alpha haplotype. Surprisingly, radioactive SSCP analysis under 2 room-temperature conditions performed as well as methods using fluorescent labeling that were expected to be more sensitive. We conclude that in African American individuals under age 50, variation in the HNF1a gene is common but unlikely to be a significant cause of T2DM.

Anticoagulant effects of hirulog, a novel thrombin inhibitor, in patients with coronary artery disease.

Selective thrombin inhibitors are a new class of antithrombotic drugs that, unlike heparin, can effectively inhibit clot-bound thrombin and escape neutralization by activated platelets. Hirulog is a 20 amino acid hirudin-based synthetic peptide that has shown promise in experimental models of thrombosis. Little information is available about the effects of hirulog in patients with coronary artery disease. Forty-five patients undergoing cardiac catheterization, who were taking aspirin, were randomized to receive either (1) hirulog, 0.05 mg/kg intravenous bolus followed by 0.2 mg/kg/hour intravenous infusion until the end of the catheterization; (2) hirulog, 0.15 mg/kg intravenous bolus followed by 0.6 mg/kg/hour intravenous infusion; or (3) heparin; 5,000 U intravenous bolus. Serial activated partial thromboplastin time (APTT), prothrombin time, activated clotting time and fibrinopeptide A were measured. Hirulog produced a dose-dependent prolongation of all coagulation parameters; the 0.6 mg/kg/hour dose prolonged the APTT to 218 +/- 50% of baseline after 2 minutes and 248 +/- 50% of baseline after 15 minutes. The half-life of the effect on APTT was 40 minutes. The hirulog blood level correlated well with the APTT, prothrombin time and activated clotting time (r = 0.77, 0.73, and 0.82 respectively, all p < 0.001). Both doses of hirulog potently suppressed the generation of fibrinopeptide A (p < 0.05). There were no major hemorrhagic, thrombotic or allergic complications in patients treated with hirulog or heparin. Thus, hirulog, a direct thrombin inhibitor, provides a predictable level of anticoagulation and appears to have a potent yet well-tolerated anticoagulant profile in patients with coronary artery disease.

Medical Complaints After a Marathon Run in Cool Weather.

In brief: Little information is available about medical complaints after marathons held in cool weather. To obtain such information medical records were maintained on every runner requesting medical attention after the Bostonfest Marathon on Oct 30, 1983. One hundred sixty-four (11.5%) of the runners finishing the race requested medical attention at the finish line. Men and women requested attention with equal frequency, but younger (20 to 30 years old) and faster (finishing in less than 3:00) runners sought medical attention more often than the older and slower runners. The complaints and symptoms of runners after the race were similar to those of runners following warm-weather races.