Genetic influence on smoking

Factors influencing the outcome from ultrasonography-guided fine-needle aspiration of benign thyroid cysts and partially cystic thyroid nodules: A multicenter study

PURPOSE

The effect of ultrasonography (US)-guided fine-needle aspiration (US-FNA) for the collapse of benign cystic thyroid nodules is still unclear. This study aimed to assess the positive response rate following US-FNA of the cystic component of thyroid cysts and of partially cystic thyroid nodules (PCTNs), and to evaluate the factors influencing the outcome.

METHODS

From June to December 2013, seven radiologists at seven institutions prospectively performed US-FNA on 320 cystic thyroid nodules in 320 patients. Among them, 179 underwent at least one follow-up US examination following US-FNA of the cystic component at each institution by the same radiologist. A variety of factors, including US features of cystic thyroid nodules, the characteristics of the aspirates, and the follow-up US findings, were analyzed.

RESULTS

Of 179 cystic thyroid nodules, there were 53 thyroid cysts and 126 PCTNs. Of 179 cystic thyroid nodules, no malignancies were detected. On follow-up US, the mean size reduction rate of the cystic component was 31.9%, and 102 out of 179 thyroid nodules (57.0%) were assigned to the response group. On univariate analysis, the degree of aspiration and time interval between US-FNA and the final follow-up US showed the significant differences between the response and no response groups. On multivariate analysis, the only factor that influenced the outcome was the nodule type. The cystic component's positive response rate after simple aspiration was higher in the thyroid cysts than in the PCTNs.

CONCLUSIONS

US-FNA may be effective at collapsing the cystic components of benign thyroid cysts and PCTNs.

Ultrasound-guided fine-needle aspiration of benign thyroid cysts or partially cystic thyroid nodules: a preliminary study for factors predicting successful collapse

No published study has evaluated factors that predict successful collapse of the cystic component of benign cystic thyroid nodules after ultrasound (US)-guided fine-needle aspiration (US-FNA). This study aimed to assess the collapse rate of the cystic component of benign cystic thyroid nodules after US-FNA and to evaluate the factors related to successful collapse of cystic component. Over a 2-year period, US-FNAs of fluid from the cystic components of 97 thyroid nodules with measured volume of >1 mL were performed, and for 80 nodules at least 1 follow-up US exam was performed. Each thyroid nodule was classified according to the largest diameter, percentage of cystic component, volume and colors of aspirate, degree of aspiration, and the time to the last US follow-up. The rate of complete collapse of the cystic component was 18.8 % (15/80). The success rate increased as the degree of aspiration increased (p = 0.0328), and there was a statistically significant difference between bloody and non-bloody aspirates (p = 0.0019). The time to the last US follow-up had statistically significant correlation with complete collapse rate (p < 0.0001), but largest diameter of thyroid nodule, percentage of cystic component, and volume of aspirate showed no significant correlation. Only 32 nodules were reexamined by US after more than 3 months, of which 11 showed complete collapse (34.4 %). In this study, rates of successful collapse of the cystic component after US-FNA of benign cystic thyroid nodules were higher in cases of complete aspiration and in those with bloody aspirates.

Heritability of longitudinal changes in coronary-heart-disease risk factors in women twins

Numerous studies have demonstrated genetic influences on levels of coronary heart disease (CHD) risk factors, but there also may be genetic effects on the intraindividual variation in these risk factors over time. Changes in risk factors are likely to reflect genetic-environmental interactions and may have important implications for understanding CHD risk. The present study examines the heritability of changes in CHD risk factors, using data from the two examinations by the Kaiser Permanente Women Twins Study, performed a decade apart. The sample consisted of 348 pairs of women twins who participated in both examinations, including 203 MZ pairs and 145 DZ pairs. Average ages at the two examinations were 41 and 51 years, respectively. By means of three different statistical analytic approaches, moderate heritability estimates were demonstrated for changes in LDL cholesterol (h2 = .25-.36) and in HDL cholesterol (h2 = .23-.58), some of which were statistically significant. Although small to moderate heritability estimates were found for systolic blood pressure (.18-.37; P < .05 for some estimates), no genetic influence on changes in diastolic blood pressure was detected. Based on longitudinal twin data in women, this study demonstrates a genetic influence on changes in both lipoprotein risk factors and systolic blood pressure over a decade. In addition to environmental factors, which clearly are operating, the effect of various "variability genes" may be acting independently of the genetic influences on the absolute levels of these risk factors. Both mapping the gene(s) underlying intraindividual variations in these CHD risk factors and understanding their function(s) could lead to targeted intervention strategies to reduce CHD risk among genetically susceptible individuals.

Evidence for genetic influences on smoking in adult women twins

The purpose of the present study was to examine genetic influences on smoking behavior in women twins, and to compare the results before and after adjusting for environmental covariates. Subjects were participants in the Kaiser Permanente Women Twins Study in Oakland, California. Exam 1 (1978-1979) included 434 pairs of women, and exam 2 (1989-1990) included 352 pairs of women. For comparison with a previous study in male twins, pairwise concordance ratios (OCR) for smoking status between monozygotic (MZ) and dizygotic (DZ) twins were calculated. Multivariate logistic regression analysis was also used to assess the association of smoking behaviors between co-twins, adjusting for age, education, and frequency of contact. At exam 1, OCR's were consistent with previous results in male twins, and supported genetic influences on smoking initiation (OCR = 1.6; 95% Confidence Interval (95% CI) = 1.0, 2.3) and maintenance (OCR = 1.8; 95% CI = 1.3, 2.4). In contrast to the males, however, no clear evidence for genetic influences on smoking intensity or never smoking were present. The adjusted logistic regression models appeared to confirm the findings from the pairwise comparisons. The results were similar for exam 2. These results are consistent with modest genetic influences on smoking initiation and maintenance. Differences between these results and those for the male twins suggest possible genetic-environmental interactions.