Biomedical subjects

W F Posthuma

Publications and source records attributed to W F Posthuma.

2 recordsLinked to original sources

PubMed1997

Do patients with systemic sclerosis have abnormal gallbladder function?

OBJECTIVE: To determine gallbladder motility in patients with systemic sclerosis. DESIGN: Case control study. SETTING: University hospital, out-patient department of rheumatology. PATIENTS: Ten patients with systemic sclerosis according to the criteria of the American Rheumatism Association with documented involvement of the gastrointestinal tract and 10 healthy controls matched for age, sex and body mass index. INTERVENTION: Cephalic vagal cholinergic simulation by modified sham feeding and hormonal stimulation by infusion of cholecystokinin. MEASUREMENTS: Gallbladder volume obtained by ultrasonography and determination of plasma cholecystokinin concentrations. RESULTS: Fasting gallbladder volumes were not significantly different between patients with systemic sclerosis and controls (19.6 +/- 1.9 cm3 and 23.3 +/- 2.9 cm3, respectively, mean plus or minus standard error of the mean). Neither were there significant differences in reduction of gallbladder volume in response to modified sham feeding (35 +/- 4% and 33 +/- 4%, respectively) nor during cholecystokinin infusion (56 +/- 4% and 60 +/- 6%, respectively). The increase in plasma cholecystokinin levels during infusion was not different in the two groups. CONCLUSION: Gallbladder motility in patients with systemic sclerosis is preserved in response to both cholinergic and hormonal stimulation, even when other gastrointestinal motor disturbances are present. These results suggest that patients with systemic sclerosis are not at increased risk for cholelithiasis because of gallbladder dysmotility.

Case-Control Studies↗

PubMed1994

Cardioprotective effect of hormone replacement therapy in postmenopausal women: is the evidence biased?

OBJECTIVE: To quantify the effect of selection of relatively healthy women in studies reporting reduced relative risk for cardiovascular disease in postmenopausal women taking hormone replacement therapy. DESIGN: Review of the follow up studies reported in three recent meta-analyses to determine the effect of oestrogen therapy on both total cancer and cardiovascular disease. The same standard statistical methods as in the original analyses were used. MAIN OUTCOME MEASURES: Relative risks of total cancer and cardiovascular disease. RESULTS: In most of the follow up studies the relative risk for total cancer was below 1. The studies that showed the largest reduction in cardiovascular disease also showed the largest reduction in cancer, indicating a healthy cohort effect. Although heterogeneity within the studies prevented pooling, the best estimate for the protective effect on total cancer was a relative risk of 0.83 among women taking oestrogen (95% confidence interval 0.71 to 0.96), while in the same studies the relative risk for cardiovascular disease was 0.57 (0.50 to 0.64). CONCLUSIONS: Unintended selection of relatively healthy women for oestrogen therapy may have influenced the reported beneficial effect of oestrogen therapy on cardiovascular disease. It is unclear how much of the cardioprotection is due to this selection. Universal preventive hormonal replacement therapy for postmenopausal women is unwarranted at present.

Cardiovascular Diseases↗