Biomedical subjects

Alexandra P Bremner

Publications and source records attributed to Alexandra P Bremner.

6 recordsLinked to original sources

PubMed2006

Trends in registered blindness and its causes over 19 years in Western Australia.

PURPOSE: To estimate the population-based incidence rates of blindness registration and their trends over time in Western Australia. METHODS: A retrospective review was performed on all cases of bilateral blindness registered with the Association for the Blind of Western Australia between 1984 and 2002. The causes and mean age at blindness registration were ascertained and incidence rates of blindness due to various causes were calculated. RESULTS: A total of 3852 blind certificates were examined. From 1984 to 1994, the annual incidence of registered bilateral blindness decreased significantly at an average rate of 9.4% per year (p < 0.0001), but then rose at a mean rate of 4.1% per year (p < 0.0001). ARMD blindness similarly fell by 8.9% per year (p < 0.0001), but then rose after 1994 by 4.5% per year (p < 0.0001). The incidence due to glaucoma decreased at an average rate of 10.3% per year (p < 0.0001) until 1994 and then rose at 7.4% per year at borderline significance (p = 0.025). CONCLUSIONS: There has been a nonlinear decrease in the incidence of registered blindness, in particular glaucoma-related blindness, in Western Australia. Rates of total registered blindness and that due to ARMD fell from 1984 to 1994, but have risen since.

Blindness↗

PubMed2006

Subclinical thyroid dysfunction and blood pressure: a community-based study.

OBJECTIVE: Overt hypothyroidism and hyperthyroidism are associated with hypertension, but it is uncertain whether the same is true of subclinical hypothyroidism and hyperthyroidism. DESIGN, SUBJECTS AND MEASUREMENTS: Cross-sectional study of 2033 participants (aged 17-89 years) in the Busselton Thyroid Study who did not have a history of thyroid disease. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and the prevalence of hypertension (defined as SBP >or=140 mmHg, DBP >or=90 mmHg or on treatment for hypertension) in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models. Subjects with treated hypertension (N = 299) were excluded from analyses of SBP and DBP but included in analyses of hypertension prevalence. RESULTS: Mean SBP, DBP and the prevalence of hypertension did not differ significantly between subjects with subclinical hypothyroidism (N = 105) and euthyroid subjects (N = 1859), nor did they differ between subjects with serum TSH concentrations in the upper reference range (2.0-4.0 mU/l; N = 418) and those with TSH concentrations in the lower reference range (0.4-2.0 mU/l; N = 1441). The prevalence of hypertension was higher in subjects with subclinical hyperthyroidism than euthyroid subjects (prevalence odds ratio 2.8, 95% confidence interval 1.3-6.0 adjusted for age, age(2) and sex), but this was based on a small number of subjects with subclinical hyperthyroidism (N = 35). CONCLUSIONS: Subclinical hypothyroidism is not associated with hypertension. The observed association between subclinical hyperthyroidism and hypertension requires confirmation in a larger sample.

Adolescent↗

PubMed2006

A randomized controlled equivalence trial of short-term complications and efficacy of tension-free vaginal tape and suprapubic urethral support sling for treating stress incontinence.

OBJECTIVE: To establish the equivalence between the tension-free vaginal tape (TVT) and the suprapubic urethral support sling (SPARC). Approximately 35% of women have stress urinary incontinence (SUI), and although TVT is now perceived as the standard treatment, the SPARC is a very similar procedure and is thought to have fewer peri-operative complications. PATIENTS AND METHODS: Patients with clinical SUI were recruited from public and private urology/urogynaecology clinics, and participated in the trial of TVT vs SPARC. The primary outcome was bladder perforation; secondary outcomes were blood loss, voiding difficulty, urgency, and cure of SUI symptoms. Sample size calculations, based on an estimated 2% perforation rate, showed that 290 patients would be needed to detect a clinically significant difference of 5%. Stratification was by previous incontinence surgery and the experience of the surgeon. RESULTS: There were 301 operations; the difference in bladder perforations was not statistically significant, at one/147 TVT (0.7%), and three/154 SPARC (1.9%), with the difference in rate of 0.013 (95% confidence interval (CI) - 0.01 to 0.04; odds ratio 2.89, 95% CI 0.30-28.21; P = 0.62), and nor were differences in estimated blood loss of >100 mL (TVT, 32/147, 21.8%; SPARC 28/154, 18.2%); de novo urgency (TVT 15/37, 40.5%; SPARC 14/33, 42.4%), objective cure (TVT 143/147, 97.3%; SPARC 148/152, 97.4%) or vaginal mesh erosion (TVT 7/147, 4.8%; SPARC 16/152, 10.5%). Acute urinary retention (TVT none of 147; SPARC 10/154, 6.5%; odds ratio infinity, 95% CI 2.2-infinity; P = 0.002) and subjective cure (TVT 128/147, 87.1%; SPARC 117/153, 76.5%; odds ratio 2.07, 95% CI 1.13-3.81; P = 0.03) were statistically significantly different. CONCLUSION: These results are consistent with clinical equivalence between TVT and SPARC for bladder perforation. There was no statistically significant difference between TVT and SPARC in blood loss, urgency or objective cure of SUI symptoms at 6 weeks. However, SPARC was more difficult to adjust correctly, and a statistically significant number of patients required loosening of the tape in theatre (P = 0.002). TVT had a lower rate of vaginal erosion and a statistically significantly higher cure rate of subjective SUI symptoms than SPARC. Overall, voiding difficulty (loosening of the tape), urgency and vaginal mesh erosion were the most important clinical problems. This trial showed the importance of testing new devices which appear to be similar, but which might have relevant differences. There was no financial assistance for this study, and a long-term follow up is planned.

Adult↗

PubMed2005

Subclinical thyroid dysfunction as a risk factor for cardiovascular disease.

BACKGROUND: There have been few large epidemiological studies examining the association between thyroid dysfunction and cardiovascular disease. In particular, it is uncertain if subclinical hypothyroidism is a risk factor for cardiovascular disease. METHODS: Serum thyrotropin and free thyroxine concentrations were measured in 2108 archived serum samples from a 1981 community health survey in Busselton, Western Australia (Busselton Health Study). In a cross-sectional study, we examined the prevalence of coronary heart disease in subjects with and without subclinical thyroid dysfunction. In a longitudinal study, we examined the risk of cardiovascular mortality and coronary heart disease events (fatal and nonfatal combined) to the end of 2001 (excluding subjects who had coronary heart disease at baseline). RESULTS: In the cross-sectional analysis, subjects with subclinical hypothyroidism (n = 119) had a significantly higher prevalence of coronary heart disease than euthyroid subjects (n = 1906) (age- and sex-adjusted prevalence odds ratio, 1.8; 95% confidence interval, 1.0-3.1; P = .04). In the longitudinal analysis of subjects with subclinical hypothyroidism (n = 101), there were 21 cardiovascular deaths observed compared with 9.5 expected (age- and sex-adjusted hazard ratio, 1.5; 95% confidence interval, 1.0-2.4; P = .08) and 33 coronary heart disease events observed compared with 14.7 expected (age- and sex-adjusted hazard ratio, 1.7; 95% confidence interval, 1.2-2.4; P < .01). The increased risk of coronary heart disease events remained significant after further adjustment for standard cardiovascular risk factors. Subjects with subclinical hyperthyroidism (n = 39) had no adverse outcomes. CONCLUSION: Subclinical hypothyroidism may be an independent risk factor for coronary heart disease.

Adolescent↗

PubMed2005

Parity and the risk of autoimmune thyroid disease: a community-based study.

CONTEXT: Recent studies have suggested that fetal microchimerism (transplacental passage of fetal cells followed by engraftment into maternal tissues) may play a role in the pathogenesis of autoimmune thyroid disease. If that is true, then parity should be a risk factor for autoimmune thyroid disease. OBJECTIVE: The objective of this study was to examine parity as a risk factor for autoimmune thyroid disease. DESIGN, SETTING, AND PARTICIPANTS: TSH, thyroid peroxidase antibody, and thyroglobulin antibody concentrations were measured on archived sera from 1045 female participants in a 1981 community health survey in Busselton, Western Australia. OUTCOME MEASURES: Odds ratios (ORs) for positive thyroid antibodies (increased concentration of either antibody) or thyroid dysfunction (abnormal serum TSH) were used. RESULTS: After adjustment for age, women who had previously been pregnant did not have a significantly increased risk of positive thyroid antibodies [OR, 1.20; 95% confidence interval (CI), 0.74-1.97; P = 0.46], raised TSH (OR, 0.93; 95% CI, 0.46-1.87; P = 0.84), or reduced TSH (OR, 0.87; 95% CI, 0.33-2.30; P = 0.79) compared with women who had never been pregnant. For each additional pregnancy, the OR was 1.02 (95% CI, 0.94-1.11; P = 0.57) for positive antibodies, 1.02 (95% CI, 0.91-1.14; P = 0.67) for raised TSH, and 1.03 (95% CI, 0.87-1.22; P = 0.73) for reduced TSH. Analysis using number of live births gave similar results. The results were similar in younger and older women. CONCLUSIONS: Parity is not a risk factor for thyroid autoimmunity or thyroid dysfunction. These data do not support a key pathogenic role for fetal microchimerism in chronic autoimmune thyroid disease.

Adult↗

PubMed2005

Thyroid dysfunction and serum lipids: a community-based study.

OBJECTIVE: It is uncertain whether subclinical hypothyroidism (SCH) is associated with hypercholesterolaemia, particularly in subjects with SCH and serum TSH < or = 10 mU/l. DESIGN, PATIENTS AND MEASUREMENTS: Cross-sectional study of 2108 participants in a 1981 community health survey in Busselton, Western Australia. Serum total cholesterol and triglycerides were measured in all subjects and high density lipoprotein cholesterol (HDL-C) measured (and low density lipoprotein cholesterol (LDL-C) calculated) in a subgroup of 631 subjects at the time of the survey. In 2001, TSH and free T4 concentrations were measured on archived sera stored at -70 degrees C. Serum lipid concentrations in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models. RESULTS: In the group as a whole, serum total cholesterol was higher in subjects with SCH (N = 119) than in euthyroid subjects (N = 1906) (mean +/- SD 6.3 +/- 1.3 mmol/l vs. 5.8 +/- 1.2 mmol/l, P < 0.001 unadjusted, P = 0.061 adjusted for age, age(2) and sex). Serum total cholesterol was similarly elevated in subjects with SCH and TSH < or = 10 mU/l (N = 89) (6.3 +/- 1.3 mmol/l, P < 0.001 unadjusted, P = 0.055 adjusted for age, age(2) and sex). In the subgroup analysis, LDL-C was higher in subjects with SCH (N = 30) than in euthyroid subjects (N = 580) (4.1 +/- 1.2 mmol/l vs. 3.5 +/- 1.0 mmol/l, P < 0.01 unadjusted, P = 0.024 adjusted for age, age(2) and sex). LDL-C was significantly increased in subjects with SCH and TSH < or = 10 mU/l (N = 23) (4.3 +/- 1.3 mmol/l, P < 0.001 unadjusted, P = 0.002 adjusted for age, age(2) and sex). CONCLUSION: SCH is associated with increased serum LDL-C concentrations, which is significant after adjustment for age, age(2) and sex.

Adolescent↗