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Thomson WM, Williams SM, Dennison PJ, Peacock DW. Were NZ's structural changes to the welfare state in the early 1990s associated with a measurable increase in oral health inequalities among children? Aust N Z J Public Health 2002; 26:525-30. [PMID: 12530796 DOI: 10.1111/j.1467-842x.2002.tb00361.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To test the hypothesis that the 1990-91 social and economic policy changes in New Zealand were associated with a subsequent increase in socioeconomic and ethnic inequalities in the dental caries experience of five-year-old children. METHOD Dental caries data from the School Dental Service treating the greater Wellington area were analysed for the period 1995-2000. Multivariate models were developed for deciduous caries prevalence (logistic regression) and severity (negative binomial regression). RESULTS In the years 1995, 1996, 1997, 1998, 1999 and 2000, complete data were available for 2,627, 3,335, 4,404, 4,155, 3,154 and 2,804 children, respectively. Ethnic and socio-economic differences in caries prevalence and severity were substantial and persistent during the observation period. Where caries severity was concerned, there was a significant interaction between time and Maori ethnicity, indicating that (on average) the oral health of Maori children deteriorated in comparison to their European counterparts. CONCLUSIONS The early-1990s social and economic policy changes were associated with an apparent widening of ethnic inequalities in caries severity among five-year-old children. IMPLICATIONS Economic rationalism appears to have oral health disadvantages for non-European children. Before implementation of proposed major social and economic policy changes, policymakers should consider their health implications.
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Jones IE, Williams SM, Dow N, Goulding A. How many children remain fracture-free during growth? a longitudinal study of children and adolescents participating in the Dunedin Multidisciplinary Health and Development Study. Osteoporos Int 2002; 13:990-5. [PMID: 12459942 DOI: 10.1007/s001980200137] [Citation(s) in RCA: 180] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
While much is known regarding the incidence and pattern of fractures during growth, information is sparse as to how many children fracture repeatedly and how many remain fracture-free during growth. The Dunedin Multidisciplinary Health and Development Study, a birth cohort, whose members were questioned regularly throughout growth (at ages 5, 7, 9, 11, 13, 15 and 18 years) concerning injuries including fractures, has provided a unique opportunity to answer these questions. Life-table analysis showed that approximately half the children remained fracture-free throughout growth [girls 60.1%, (95% CI 54.7-65.0) and boys 49.3% (95% CI 44.0-54.4)]. Data on fracture history, for participants seen at every phase, was available for 601 members through to the age of 18 years (61.1% of the cohort seen at age 5 years). Two hundred and ninety-one of these 601 participants reported 498 fractures, with 172 sustaining a single fracture, and 119 more than one fracture (15.8% girls and 23.4% boys). The most common site of fracture was the wrist/forearm (24.1% of all fractures). We conclude that although bone fractures are a common adverse event in childhood, half of all children remain fracture-free throughout growth.
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Goulding A, Taylor RW, Jones IE, Manning PJ, Williams SM. Spinal overload: a concern for obese children and adolescents? Osteoporos Int 2002; 13:835-40. [PMID: 12378374 DOI: 10.1007/s001980200116] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heavy children require stronger bones than leaner children. The present cross-sectional observational study was undertaken to examine the magnitude of compensatory increases in the spinal bone mineral content (BMC) and area shown by overweight and obese children and adolescents. Vertebral area and BMC of lumbar vertebrae L2-L4 were measured by dual-energy X-ray absorptiometry in 202 boys and 160 girls aged 3-19 years. Subjects were categorized as of normal weight, overweight or obese using international cutoffs for body mass index. Compared with children of healthy weight our overweight and obese children had lower vertebral BMC for their bone area, body height, body weight and pubertal development: ratios and 95% CI for overweight and obese groups were 0.92 (95% CI 0.87-0.97) and 0.88 (95% CI 0.80-0.96) for girls and 0.96 (95% CI 0.91-1.02, NS) and 0.87 (95% CI 0.78-0.96) for boys, respectively. Spinal area was low in overweight and obese girls compared with girls of healthy weight but overweight and obese boys had enlarged their vertebral area appropriately for their increased body size. We conclude that during growth overweight and obese children do not increase their spinal BMC to fully compensate for their excessive weight. Limiting excessive adiposity in childhood and adolescence should help to avoid excessive loading and stresses on the lumbar spine.
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Abstract
AIMS To determine whether the risk factors for SIDS occurring at night were different from those occurring during the day. METHODS Large, nationwide case-control study, with data for 369 cases and 1558 controls in New Zealand. RESULTS Two thirds of SIDS deaths occurred at night (between 10 pm and 7 30 am). The odds ratio (95% CI) for prone sleep position was 3.86 (2.67 to 5.59) for deaths occurring at night and 7.25 (4.52 to 11.63) for deaths occurring during the day; the difference was significant. The odds ratio for maternal smoking for deaths occurring at night was 2.28 (1.52 to 3.42) and that for the day 1.27 (0.79 to 2.03); that for the mother being single was 2.69 (1.29 to 3.99) for a night time death and 1.25 (0.76 to 2.04) for a daytime death. Both interactions were significant. The interactions between time of death and bed sharing, not sleeping in a cot or bassinet, Maori ethnicity, late timing of antenatal care, binge drinking, cannabis use, and illness in the baby were also significant, or almost so. All were more strongly associated with SIDS occurring at night. CONCLUSIONS Prone sleep position was more strongly associated with SIDS occurring during the day, whereas night time deaths were more strongly associated with maternal smoking and measures of social deprivation.
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Thomson WM, Williams SM. Partial- or Full-Mouth Approaches to Assessing the Prevalence of and Risk Factors for Periodontal Disease in Young Adults. J Periodontol 2002; 73:1010-4. [PMID: 12296585 DOI: 10.1902/jop.2002.73.9.1010] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND While partial-mouth recording is often used in epidemiological studies of periodontal disease because of the efficiencies afforded in data collection, there has been no investigation of the extent to which information is lost in studies of young adults using the combined attachment loss (CAL) approach. METHODS A random sample of 25- and 26-year-olds was periodontally examined at 3 sites per tooth in all 4 quadrants. The analysis obtained full-mouth prevalence estimates for gingival recession (GR), probing depth (PD), and CAL. The half-mouth analyses took 3 forms: 1) estimates from each of the left and right sides were obtained and compared; 2) estimates were obtained separately and compared for quadrants 1 and 3 (upper right and lower left), and quadrants 2 and 4 (upper left and lower right); and 3) estimates were obtained from a diagonal half-mouth count, whereby quadrants 1 and 3 were analyzed for study participants whose identification number was odd, and quadrants 2 and 4 were analyzed for the remainder. The utility of the half-mouth and full-mouth approaches in analytical epidemiology was examined by estimating the strength of the association between periodontitis prevalence and smoking, male gender, and episodic use of dental care. RESULTS Of the 169 participants examined, 100 (59.2%) were female, 54 (32.0%) were smokers, and 78 (46.2%) were episodic dental visitors. The difference in prevalence estimates obtained from the different methods was considerably greater for GR than for PD and CAL. The unadjusted odds ratio (OR) for the prevalence of 1 or more teeth with > or = mm of CAL among smokers was 2.3 (95% confidence interval [CI] 1.0, 5.3) using the full data set and 2.4 (95% CI 0.9, 6.1) using the diagonal half-mouth approach. Similarly close odds ratios were observed for males and, to a lesser extent, for episodic dental visitors. CONCLUSIONS Wherever possible, full-mouth data should be collected for descriptive epidemiological studies of periodontal disease, but where resource and time constraints mean that half-mouth examinations must be used, analytical studies of periodontitis should not be unduly affected by the loss of information. However, where the primary focus of the latter is upon gingival recession, the full-mouth design should be used in order to capture all relevant information, and attention should be directed to making economies in other areas of the data collection process.
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Venn BJ, Mann JI, Williams SM, Riddell LJ, Chisholm A, Harper MJ, Aitken W, Rossaak JI. Assessment of three levels of folic acid on serum folate and plasma homocysteine: a randomised placebo-controlled double-blind dietary intervention trial. Eur J Clin Nutr 2002; 56:748-54. [PMID: 12122551 DOI: 10.1038/sj.ejcn.1601388] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2001] [Revised: 11/05/2001] [Accepted: 11/12/2001] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine the minimum effective dose of folic acid required to appreciably increase serum folate and to produce a significant reduction in plasma total homocysteine (tHcy). DESIGN Double-blind, randomised placebo-controlled intervention trial. SETTING Community-based project in a New Zealand city. SUBJECTS Seventy free living men and women with tHcy> or =10 micromol/l. Mean age (range) was 58 (29-90) y. INTERVENTIONS Daily consumption over 4 weeks of 20 g breakfast cereal either unfortified (placebo) or fortified with 100, 200 or 300 microg folic acid. Dietary intake was determined by weighed diet records and consumption of commercially fortified products was avoided. MAIN OUTCOME MEASURES Plasma tHcy and serum folate concentrations. RESULTS Average serum folate concentrations (95% CI) increased significantly in the treatment groups relative to the control group by 28(9-51)%, 60(37-87)% and 79(51-114)% for supplementation with 100, 200 and 300 microg folic acid, respectively. A reduction in tHcy was observed, being 16(8-22)%, 12(4-18)% and 17(9-24)% in the three treatment groups, respectively. CONCLUSIONS A regular intake of as little as 100 microg folic acid per day was sufficient to lower tHcy in persons at the upper end of the normal range for tHcy. Low-level fortification may also be appropriate for lowering the risk of neural tube defects given that, when aggregated from all sources, the total intake of folic acid may be sufficiently high to adequately improve the folate status of young women.
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Abstract
Long-term divergent selection for high (HH) and low (LL) BW at 56 d of age in White Plymouth Rock chickens resulted in deviations from a typical chronological timeline for reproductive development. Line HH chickens of the 42nd generation of selection (S(42)) were heavier at 28, 56, 168, and 266 d of age, as well as at sexual maturity than those from line LL of the same generation, and commenced egg production at a younger age (188 d vs. 217 d). Once the LL chickens reached sexual maturity, 99.5% of their ovulations resulted in normal oviposits, in contrast to 94.6% for HH females. Heterosis, as measured by differences of F(1) progeny from the parental lines, can have a positive or negative sign. Although negative heterosis does not imply inferiority, results may be confusing because, depending on the trait, positive or negative can biologically be the phenotype that is preferred. Heterosis was calculated using coefficients of variation and means for reciprocal crosses from S(41) parents of the selected lines. Growth and reproductive traits were measured in this experiment. In almost all cases, heterosis calculated using coefficients of variation had a narrower range of magnitudes.
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Klemp P, Williams SM, Stansfield SA. Articular mobility in Maori and European New Zealanders. Rheumatology (Oxford) 2002; 41:554-7. [PMID: 12011380 DOI: 10.1093/rheumatology/41.5.554] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To determine the prevalence of hypermobility and of the hypermobility syndrome (HMS) in Maori and European New Zealanders. METHODS The prevalences of generalized hypermobility (Beighton's score > or = 4), of hypermobility at individual sites and of HMS were determined in 804 Maori and European subjects. Musculoskeletal system (MSS) manifestations were documented in all subjects by personal interview and an MSS examination. Radiographs were obtained where appropriate. RESULTS The percentage of hypermobile subjects was 6.2 for Maori (9.0 for females and 2.2 for males) and 4.0 for Europeans (5.6 and 1.9). Hypermobility was more prevalent in females (P=0.0001). Hypermobility of the elbow was more prevalent in Maori (P=0.003) and hyperextension of the fifth finger and apposition of thumb to forearm were more prevalent in females (P<0.001). HMS was present in two of 41 (4.9%, 95% confidence interval 0.6-17.6%) hypermobile subjects. Both were Maori females and therefore 2/23 hypermobile Maori females (8.7%, 1.1-31.4%) had HMS. CONCLUSION The prevalence of hypermobility in Maori is similar to that in European New Zealanders and Caucasians elsewhere. Larger studies are necessary to determine the prevalence of HMS in Maori, particularly Maori females.
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Perez DJ, Williams SM, Christensen EA, McGee RO, Campbell AV. A longitudinal study of health related quality of life and utility measures in patients with advanced breast cancer. Qual Life Res 2002; 10:587-93. [PMID: 11822792 DOI: 10.1023/a:1013193007095] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Health related quality of life (HRQOL) measures are now accepted as indicators of efficacy in the palliative treatment of cancer. Utility measures may also provide valuable information yet they have been applied less frequently. To assess the application of a time trade-off (TTO) utility measure and its concordance with the Spitzer uniscale and quality of life index (QLI) 38 women with advanced, symptomatic breast cancer were studied over a 12 month period. The correlation coefficient for QLI and TTO values was 0.54 and for uniscale and TTO 0.62. Using generalized estimating equations the regression of TTO scores on QLI and uniscale scores was significant at baseline. In longitudinal analyses results were significant only for QLI. Although all participants completed the HRQOL measures only 24 (63%) were prepared to trade time. The remaining 14 (32%) stated they felt too well to trade. Those prepared to trade time recorded significantly worse mean HRQOL scores throughout the study compared to those who felt too well to trade and had tumors which showed a poorer response to therapy. In this preliminary study utility and HRQOL scores were generally favorable throughout the 12 month study period and showed fair to moderate concordance. Further research in larger patient groups is required to better define the relationships between utility and HRQOL measures.
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Williams SM, Gray W, Gleeson FV. Macroscopic assessment of pulmonary fine needle aspiration biopsies: correlation with cytological diagnostic yield. Br J Radiol 2002; 75:28-30. [PMID: 11806955 DOI: 10.1259/bjr.75.889.750028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Fine needle aspiration biopsy (FNAB) is widely used in the diagnosis of pulmonary neoplasia. Previous studies have advocated the use of immediate cytological review at the time of biopsy to reduce the number of needle passes performed, whilst stating that in the absence of this, simple macroscopic assessment of sample quality was used. This latter practice is widespread, but there is no data regarding its accuracy or the level of intra-observer consistency. We assessed the degree of correlation between a macroscopic grading of the FNAB sample at the time of lung biopsy by the radiologist performing the procedure and subsequent diagnostic yield. 45 consecutive patients in whom pulmonary neoplastic disease was strongly suspected were included. Macroscopic sample appearances were graded on a five-point scale from 1 (blood with no particulate material) to 5 (solid tissue pieces). The positivity rate increased stepwise along with macroscopic grading from 50% for samples graded 1 to 100% for samples graded 5. Grouping the predominately haemorrhagic samples (graded 1-2) together and comparing them with the particulate samples (graded 3-5) demonstrates a statistically significant difference in diagnostic yield (p<0.001). This small study shows that a simple macroscopic grading of pulmonary FNAB samples can provide a good indication of likely cytological diagnostic yield and that radiologists can develop a degree of consistency in their assessment. In the absence of direct cytological input, this may provide a basis for decisions on the number of passes performed.
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Wallace AJ, Sutherland WH, Mann JI, Williams SM. The effect of meals rich in thermally stressed olive and safflower oils on postprandial serum paraoxonase activity in patients with diabetes. Eur J Clin Nutr 2001; 55:951-8. [PMID: 11641743 DOI: 10.1038/sj.ejcn.1601250] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2000] [Revised: 04/03/2001] [Accepted: 04/08/2001] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To determine the effects of meals rich in thermally stressed safflower (TSAF) and olive (TSOL) oils on postprandial serum paraoxonase (PON1) arylesterase activity and low density lipoprotein (LDL) oxidation in patients with type 2 diabetes. DESIGN A randomised cross-over study. SETTING Diabetes clinic and general practice. SUBJECTS Fourteen patients (six men and eight women) with type 2 diabetes, aged 48-67 y, glycated haemoglobin <10% and fasting blood glucose <11 mmol/l were recruited. INTERVENTIONS Patients received a milkshake rich in TSAF or TSOL and at least a week later they received the alternate milkshake. These fats contained high levels of lipid oxidation and degradation products. Blood samples were taken fasted and 4 h after consumption of the milkshake. MAIN OUTCOME MEASURES Serum PON1 activity and lag time in LDL oxidation. RESULTS After the meal rich in TSOL, serum PON1 activity increased significantly in women (12 (2.22) micromol/ml/min, mean (95% confidence interval), P=0.03) and not in men (0 (-4.4) micromol/ml/min) during the postprandial period. The increase in PON1 activity after the TSOL meal was significantly (P=0.03) greater in women compared with men. In women, the increase in serum PON1 activity after the TSOL meal was significantly different (13 (1.25) micromol/ml/min, P=0.04) compared with the corresponding change (-1 micromol/ml/min) after the TSAF meal. The lag time in LDL oxidation and indices of oxidative stress and antioxidant capacity did not vary significantly during the meals. CONCLUSIONS Meals rich in TSOL may increase postprandial serum PON1 activity in middle-aged and older diabetic women. This change is potentially anti-atherogenic and may favour the use of olive oil over polyunsaturated fats in the diet of patients with type 2 diabetes. SPONSORSHIP The study was supported by a grant from the National Heart Foundation of New Zealand.
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Goulding A, Jones IE, Taylor RW, Williams SM, Manning PJ. Bone mineral density and body composition in boys with distal forearm fractures: a dual-energy x-ray absorptiometry study. J Pediatr 2001; 139:509-15. [PMID: 11598596 DOI: 10.1067/mpd.2001.116297] [Citation(s) in RCA: 368] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To determine whether boys with distal forearm fractures differ from fracture-free control subjects in bone mineral density (BMD) or body composition. STUDY DESIGN A case-control study of 100 patients with fractures (aged 3 to 19 years) and l00 age-matched fracture-free control subjects was conducted. Weight, height, and body mass index were measured anthropometrically. BMD values and body composition were determined by dual-energy x-ray absorptiometry. RESULTS More patients than control subjects (36 vs l4) were overweight (body mass index >85th percentile for age, P <.001). Patients had lower areal (aBMD) and volumetric (BMAD) bone mineral density values and lower bone mineral content but more fat and less lean tissue than fracture-free control subjects. The ratios (95% CIs) for all case patients/control subjects in age and weight-adjusted data were ultradistal radius aBMD 0.94 (0.91-0.97); 33% radius aBMD 0.96 (0.93-0.98) and BMAD 0.95 (0.91-0.99); spinal L2-4 BMD 0.92 (0.89-0.95) and BMAD 0.92 (0.89-0.94); femoral neck aBMD 0.95 (0.92-0.98) and BMAD 0.95 (0.91-0.98); total body aBMD 0.97 (0.96-0.99), fat mass 1.14 (1.04-1.24), lean mass 0.96 (0.93-0.99), and total body bone mineral content 0.94 (0.91-0.97). CONCLUSIONS Our results support the view that low BMC, aBMD, and BMAD values and high adiposity are associated with increased risk of distal forearm fracture in boys. This is a concern, given the increasing levels of obesity in children today.
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Heath AL, Skeaff CM, O'Brien SM, Williams SM, Gibson RS. Can dietary treatment of non-anemic iron deficiency improve iron status? J Am Coll Nutr 2001; 20:477-84. [PMID: 11601562 DOI: 10.1080/07315724.2001.10719056] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To investigate the efficacy of, first, a dietary regimen involving increased consumption of iron-rich foods and enhancers of iron absorption and decreased consumption of inhibitors of iron absorption and, second, a low dose iron chelate iron supplement, for increasing iron stores in young adult New Zealand women with mild iron deficiency (MID). METHODS The study was a 16 week randomized placebo-controlled intervention. Seventy-five women aged 18 to 40 years with MID (serum ferritin < 20 microg/L and hemoglobin > or = 120 g/L) were assigned to one of three groups: Placebo, Supplement (50 mg iron/day as amino acid chelate) or Diet. Participants in the Diet Group were given individual dietary counseling to increase the intake and bioavailability of dietary iron. Dietary changes were monitored by a previously validated computer-administered iron food frequency questionnaire. RESULTS Diet Group members significantly increased their intake of flesh foods, heme iron, vitamin C and foods cooked using cast-iron cookware and significantly decreased their phytate and calcium intakes. Serum ferritin increased in the Supplement and Diet Groups by 59% (p=0.001) and 26% (p=0.068), respectively, in comparison to the Placebo Group. The serum transferrin receptor:serum ferritin ratio decreased by 51% in the Supplement Group (p=0.001), and there was a non-significant decrease of 22% (p=0.1232) in the Diet Group. CONCLUSIONS This study is the first, to our knowledge, to demonstrate that an intensive dietary program has the potential to improve the iron status of women with iron deficiency.
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Manning PJ, Allum A, Jones S, Sutherland WH, Williams SM. The effect of hormone replacement therapy on cardiovascular risk factors in type 2 diabetes: a randomized controlled trial. ARCHIVES OF INTERNAL MEDICINE 2001; 161:1772-6. [PMID: 11485511 DOI: 10.1001/archinte.161.14.1772] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Postmenopausal women with diabetes are at high risk for cardiovascular disease, compared with their nondiabetic counterparts. Combined continuous hormone replacement therapy (HRT) is associated with improvements in serum lipoprotein levels in nondiabetic women; however, the effect in women with diabetes has not been determined. We evaluated the effect of combined continuous HRT on lipoprotein and coagulation factor concentrations and glycemic control in postmenopausal women with type 2 diabetes mellitus. METHODS In a randomized controlled crossover study, 61 subjects received combined continuous HRT or placebo. Each treatment phase was of 6 months' duration, with an 8-week washout phase between treatment phases. RESULTS Total cholesterol concentration decreased by 7% (95% confidence interval [CI], 4%-11%) during HRT. For low-density lipoprotein concentration, the mean decrease with HRT was 12% (95% CI, 6%-17%). Apolipoprotein B levels decreased in keeping with the reduction in low-density lipoprotein cholesterol concentrations. There were no significant changes in concentrations of high-density lipoprotein, its subfractions, or triglycerides. Lipoprotein(a) and fibrinogen concentrations were reduced by 21% (95% CI, 10%-31%) and 8% (95% CI, 2%-13%), respectively, with HRT. Fructosamine concentrations declined by 5% (95% CI, 2%-9%) during HRT. CONCLUSIONS In postmenopausal women with type 2 diabetes mellitus, combined continuous HRT has beneficial effects on lipoprotein concentrations and improves some markers of coagulation and glycemic control.
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Tishkoff SA, Varkonyi R, Cahinhinan N, Abbes S, Argyropoulos G, Destro-Bisol G, Drousiotou A, Dangerfield B, Lefranc G, Loiselet J, Piro A, Stoneking M, Tagarelli A, Tagarelli G, Touma EH, Williams SM, Clark AG. Haplotype diversity and linkage disequilibrium at human G6PD: recent origin of alleles that confer malarial resistance. Science 2001; 293:455-62. [PMID: 11423617 DOI: 10.1126/science.1061573] [Citation(s) in RCA: 487] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The frequencies of low-activity alleles of glucose-6-phosphate dehydrogenase in humans are highly correlated with the prevalence of malaria. These "deficiency" alleles are thought to provide reduced risk from infection by the Plasmodium parasite and are maintained at high frequency despite the hemopathologies that they cause. Haplotype analysis of "A-" and "Med" mutations at this locus indicates that they have evolved independently and have increased in frequency at a rate that is too rapid to be explained by random genetic drift. Statistical modeling indicates that the A- allele arose within the past 3840 to 11,760 years and the Med allele arose within the past 1600 to 6640 years. These results support the hypothesis that malaria has had a major impact on humans only since the introduction of agriculture within the past 10,000 years and provide a striking example of the signature of selection on the human genome.
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Campbell AJ, Galland BC, Bolton DP, Taylor BJ, Sayers RM, Williams SM. Ventilatory responses to rebreathing in infants exposed to maternal smoking. Acta Paediatr 2001; 90:793-800. [PMID: 11519984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
UNLABELLED This study assessed the effect of maternal smoking during pregnancy on ventilatory and waking responses of infants to a respiratory challenge. This challenge mimicked the time-course and concentration of gases that an infant would experience rebreathing face-down into soft bedding. Control (C; n = 97) and smokers' infants (SM; n = 96) were studied at ages I and 3 mo. Asphyxial gas (hypercapnia/hypoxia) was delivered to the supine sleeping baby via a hood by slowly altering the inspired air: CO2 maximum 5% and O2 minimum 13.5%. Respiratory pattern was recorded by inductive plethysmography as the sum of ribcage and abdominal movements. The change in ventilation with inspired CO2 was measured over 5-6 min of the test. The slope of a linear curve fit relating inspired CO2 to the logarithm of ventilation was taken as a quantitative measure of ventilatory asphyxial sensitivity (VAS). Protective responses were graded from 1: no waking and an estimated arterial carbon dioxide tension (PaCO2) > or = 60 mmHg (least protective), to 4: fully awake (most protective). The results showed VAS was higher in SM infants than controls: +0.03 (p = 0.04). The oxygen saturation (SaO2) of SM infants fell -0.4% (p = 0.02) more than SaO2 of controls despite a greater tidal volume increase: +13.0% (p = 0.04). Overall protective responses were the same between groups, but grade 1, although rare, was found in 7 SM infants and only 4 control infants; this difference was not significant. CONCLUSION The study did not confirm the postulate that infants of mothers who smoked during pregnancy have a reduced ventilatory response or raised waking thresholds.
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Elmslie JL, Mann JI, Silverstone JT, Williams SM, Romans SE. Determinants of overweight and obesity in patients with bipolar disorder. J Clin Psychiatry 2001; 62:486-91; quiz 492-3. [PMID: 11465534 DOI: 10.4088/jcp.v62n0614] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To examine lifestyle-related determinants of the excess adiposity observed in patients with bipolar disorder. METHOD Eighty-nine male and female patients with DSM-IV bipolar disorder who were attending a specialist bipolar clinic or another psychiatric outpatient clinic (19% with body mass index [BMI] > or = 30) and 445 age- and sex-matched reference subjects (12% with BMI > or = 30) participated in a cross-sectional study of nutrient intake and physical activity. Main outcome measures included macronutrient intakes (assessed with 24-hour recall), percentage of energy derived from various food sources, and physical activity levels (assessed with the Life in New Zealand Questionnaire). RESULTS Mean total energy intake was higher in female patients than in reference subjects: 8468 kJ compared with 6980 kJ (95% confidence interval [CI] = 583 to 2392 kJ). Total daily sucrose and percentage of energy from carbohydrate were higher in patients than in reference subjects; for women, 73 g and 49% (95% CI = 20 to 56 g, 3% to 10) and for men, 89 g and 47% (95% CI = 15 to 59 g, 3% to 9%). Total fluid intake and intake of sweetened drinks were higher in patients than in reference subjects (ratio of geometric means: women, 1.2 and 2.3, respectively [95% CI = 1.1 to 1.4, 1.9 to 2.8]; men, 1.1 and 2.1, respectively [95% CI = 1.0 to 1.23, 1.8 to 2.41). Patients reported fewer episodes of low- to moderate-intensity and high-intensity physical activity as compared with reference subjects (p < or = .05). CONCLUSION This study confirms that drug-induced changes in food preference can lead to an excessive energy intake largely as a result of a high intake of sucrose. Dietary advice regarding the use of energy-rich beverages along with encouragement to increase levels of physical activity may help prevent weight gain in bipolar patients. The findings also have some bearing on dietary advice aimed at avoiding overweight and obesity in the general population.
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Purves D, Lotto RB, Williams SM, Nundy S, Yang Z. Why we see things the way we do: evidence for a wholly empirical strategy of vision. Philos Trans R Soc Lond B Biol Sci 2001; 356:285-97. [PMID: 11316481 PMCID: PMC1088429 DOI: 10.1098/rstb.2000.0772] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many otherwise puzzling aspects of the way we see brightness, colour, orientation and motion can be understood in wholly empirical terms. The evidence reviewed here leads to the conclusion that visual percepts are based on patterns of reflex neural activity shaped entirely by the past success (or failure) of visually guided behaviour in response to the same or a similar retinal stimulus. As a result, the images we see accord with what the sources of the stimuli have typically turned out to be, rather than with the physical properties of the relevant objects. If vision does indeed depend upon this operational strategy to generate optimally useful perceptions of inevitably ambiguous stimuli, then the underlying neurobiological processes will eventually need to be understood within this conceptual framework.
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McAuley KA, Williams SM, Mann JI, Walker RJ, Lewis-Barned NJ, Temple LA, Duncan AW. Diagnosing insulin resistance in the general population. Diabetes Care 2001; 24:460-4. [PMID: 11289468 DOI: 10.2337/diacare.24.3.460] [Citation(s) in RCA: 456] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Difficulties in measuring insulin sensitivity prevent the identification of insulin-resistant individuals in the general population. Therefore, we compared fasting insulin, homeostasis model assessment (HOMA), insulin-to-glucose ratio, Bennett index, and a score based on weighted combinations of fasting insulin, BMI, and fasting triglycerides with the euglycemic insulin clamp to determine the most appropriate method for assessing insulin resistance in the general population. RESEARCH DESIGN AND METHODS Family history of diabetes, BMI, blood pressure, waist and hip circumference, fasting lipids, glucose, insulin, liver enzymes, and insulin sensitivity index (ISI) using the euglycemic insulin clamp were obtained for 178 normoglycemic individuals aged 25-68 years. Product-moment correlations were used to examine the association between ISI and various surrogate measurements of insulin sensitivity. Regression models were used to devise weights for each variable and to identify cutoff points for individual components of the score. A bootstrap procedure was used to identify the most useful predictors of ISI. RESULTS Correlation coefficients between ISI and fasting insulin, HOMA, insulin-to-glucose ratio, and the Bennett index were similar in magnitude. The variables that best predicted insulin sensitivity were fasting insulin and fasting triglycerides. The use of a score based on Mffm/I = exp[2.63 - 0.28ln(insulin) - 0.31ln(TAG)] rather than the use of fasting insulin alone resulted in a higher sensitivity and a maintained specificity when predicting insulin sensitivity. CONCLUSIONS A weighted combination of two routine laboratory measurements, i.e., fasting insulin and triglycerides, provides a simple means of screening for insulin resistance in the general population.
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Sutherland WH, Manning PJ, de Jong SA, Allum AR, Jones SD, Williams SM. Hormone-replacement therapy increases serum paraoxonase arylesterase activity in diabetic postmenopausal women. Metabolism 2001; 50:319-24. [PMID: 11230785 DOI: 10.1053/meta.2001.20201] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The paraoxonase (PON1) enzyme is associated with high-density lipoproteins (HDL) in the blood and is low in patients with type 2 diabetes. Hormone-replacement therapy (HRT) can increase HDL cholesterol levels, but its effect on serum PON1 arylesterase activity is uncertain. The aim of the present study was to determine the effect of 6 months' HRT with conjugated equine estrogen and medroxyprogesterone acetate on serum PON1 arylesterase activity in postmenopausal women with type 2 diabetes. Serum PON1 activity was measured immediately before and at the end of the second arm of a randomized, placebo-controlled, crossover with washout study originally designed to test the effect of HRT on plasma lipids in diabetic postmenopausal women. Baseline serum PON1 arylesterase activity was significantly (P <.001) lower in the postmenopausal diabetic women (149 +/- 38 micromol/mL/min; n = 47) than values in healthy postmenopausal women (173 +/- 32 micromol/mL/min; n = 51). Serum PON1 activity increased (10%) significantly (P =.009) in diabetic women treated with HRT compared with placebo. A significant (P =.02) interaction between baseline PON1 activity and treatment indicated a greater increase in PON1 activity during HRT in women with lower baseline activities. At baseline, serum PON1 arylesterase activity was correlated significantly with plasma HDL cholesterol levels in diabetic women (r = 0.333, P =.01, n = 47), and the increase in serum PON1 activity was correlated significantly with the change in plasma HDL cholesterol during HRT (r = 0.659, P =.0001, n = 28). These data suggest that serum PON1 activity is abnormally low in postmenopausal women with type 2 diabetes and increases during HRT, particularly in women with lower baseline levels and in those who show a concomitant increase in HDL cholesterol.
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Purves D, Williams SM, Lotto RB. The relevance of visual perception to cortical evolution and development. NOVARTIS FOUNDATION SYMPOSIUM 2001; 228:240-54; discussion 254-8. [PMID: 10929326 DOI: 10.1002/0470846631.ch16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The quality of brightness--perhaps the simplest visual attribute we perceive--appears to be determined probabilistically. In this empirical conception of the perception of light, the stimulus-induced activity of visual cortical neurons does not encode the retinal image or the properties of the stimulus per se, but associations (percepts) determined by the relative probabilities of the possible sources of the stimulus. If this theory is correct, the rationale for the prolonged postnatal construction of visual circuitry--and the evolution of this visual scheme--is to strengthen and/or create by activity-dependent feedback the empirically determined association on which vision depends.
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Mitrinović DM, Williams SM, Schlossman ML. X-ray study of oil-microemulsion and oil-water interfaces in ternary amphiphilic systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:021601. [PMID: 11308502 DOI: 10.1103/physreve.63.021601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2000] [Indexed: 05/23/2023]
Abstract
We present x-ray reflectivity and diffuse scattering measurements from the interfaces between oil-rich and microemulsion bulk phases and between oil-rich and water-rich phases in three-component microemulsion systems (consisting of water, alkane, and C(i)E(j), where the last represents n-alkyl polyglycol ether with i=4,6,10 and j=1,2,4). The x-ray measurements are analyzed with a two-parameter fit that determines the interfacial roughness, varying from 25 A to 160 A, and the interfacial tension, varying from 1.4 mN/m to 0.03 mN/m, for these samples. Although a nonmonotonic profile at the oil-microemulsion interface is not observed, these measurements exclude the presence of oscillating profiles with repeat distances greater then 500 A.
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Williams SM, Fulton RM, Render JA, Mansfield L, Bouldin M. Ocular and encephalic toxoplasmosis in canaries. Avian Dis 2001; 45:262-7. [PMID: 11332494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
In this report we describe the lesions produced by the protozoal organism, Toxoplasma gondii, in the eyes and brain of the common yellow canary (Serinus canaria). Nine of 15 birds in a flock were affected with blindness, which developed over a 3-mo span, and two birds developed torticollis. Microscopic alterations within the eye consisted of a nonsuppurative chorioretinitis with large numbers of macrophages that contained the tachyzoite form of T. gondii in the subretinal space, and aggregates of tachyzoites were found in the nerve fiber layer of the retina with and without necrosis. Tissue cysts with bradyzoites were scattered throughout the meninges and neuropil of the cerebrum and cerebellum. Both forms were confirmed by transmission electron microscopy in the eye and brain. Frozen brain samples reacted with T. gondii-specific cat sera in indirect fluorescent antibody tests. The source of infection was hypothesized to be from a stray cat the owner kept that had access to some of the bird feed. Treatment (trimethoprim 0.08 g/ml H2O and sulfadiazine 0.04 g/ml in water for 2 wk) was instituted by the referring veterinarian on the remaining birds. A second treatment regime was given for 3 wk. The owner of the canaries did not return for further treatment.
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Tarumi T, Martincic D, Whitlock JA, Addy JH, Williams SM, Gailani D. Conserved worldwide linkage disequilibrium in the human factor XI gene. Genomics 2000; 70:269-72. [PMID: 11112356 DOI: 10.1006/geno.2000.6393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have identified, in four diverse human populations, five common single-nucleotide polymorphisms (SNPs) in the coding region of the gene for the blood coagulation protease factor XI. Each SNP has an allele frequency >5% in at least one population. Three of the SNPs (C472T, A844G, and T1234C), spread out over approximately 10 kb of genomic DNA, are in marked linkage disequilibrium (LD) with one another (P < 10(-4)). Interestingly, haplotypes associated with the linked SNPs are conserved across all populations studied, despite significantly different allele frequencies between populations. The presence of such common, widely dispersed haplotypes could complicate the interpretation of LD studies and emphasizes the need for a better understanding of general patterns of LD to facilitate identification of genes for common disorders.
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