Person: Holmes, Michelle
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Holmes
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Michelle
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Holmes, Michelle
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Publication Sleep and survival among women with breast cancer: 30 years of follow-up within the Nurses’ Health Study(Nature Publishing Group, 2018) Trudel-Fitzgerald, Claudia; Zhou, Eric; Poole, Elizabeth M; Zhang, Xuehong; Michels, Karin B; Eliassen, A; Chen, Wendy; Holmes, Michelle; Tworoger, Shelley; Schernhammer, EvaPublication Sleep and survival among women with breast cancer: 30 years of follow-up within the Nurses' Health Study(Nature Publishing Group, 2017) Trudel-Fitzgerald, Claudia; Zhou, Eric; Poole, Elizabeth M; Zhang, Xuehong; Michels, Karin B; Eliassen, A; Chen, Wendy; Holmes, Michelle; Tworoger, Shelley; Schernhammer, EvaBackground: Breast cancer is a leading cause of cancer death in women. Sleep has been linked with mortality among cancer-free population; however, its association with survival among women with breast cancer is understudied. Methods: Breast cancer patients (N=3682) reported their average sleep duration post diagnosis. Subsamples also provided their pre-diagnosis sleep duration (n=1949) and post-diagnosis sleep difficulties (n=1353). Multivariate Cox models estimated hazard ratios (HR) and confidence intervals (CI) of all-cause, breast cancer, and non-breast cancer mortality. Results: At diagnosis, the mean age was 64.9 years and 91.7% were stage I or II. Women sleeping ⩾9 h per night post diagnosis had a strong higher risk of all-cause (multivariate HRs: MV-HR=1.37, CI=1.10–1.71), breast cancer (MV-HR=1.46, CI=1.02–2.07), and non-breast cancer mortality (MV-HR=1.34, CI=1.01–1.79), compared to women sleeping 8 h per night. Increased sleep duration post diagnosis (vs unchanged) and regular sleep difficulties (vs rare/none) were associated with a strong elevated risk of all-cause mortality (MV-HRincreased duration=1.35, CI=1.04–1.74; MV-HRregular difficulties=1.49, CI=1.02–2.19) and a moderate greater risk of breast cancer and non-breast cancer mortality. Conclusions: Various facets of sleep were associated with higher all-cause mortality risk. If replicated, these findings support evaluation of breast cancer patients' sleep duration and difficulties to identify those at risk for poorer outcomes.Publication Hiding in plain view: the potential for commonly used drugs to reduce breast cancer mortality(BioMed Central, 2012) Holmes, Michelle; Chen, WendyMany medications have been developed for one purpose but then are found to have other clinical activities. There is tremendous interest in whether non-cancer medications may potentially have effects on breast cancer survival. In this review article, we have presented and evaluated the evidence for several commonly used over-the-counter and prescription medications - including aspirin (and other non-steroidal anti-inflammatory drugs), beta-blockers, angiotensin-converting enzyme inhibitors, statins, digoxin, and metformin - that have been evaluated among breast cancer survivors in prospective studies. Substantial scientific evidence supports the hypothesis that some of these common and relatively safe drugs may reduce breast cancer mortality among those with the disease by an amount that rivals the mortality reduction gained by currently used therapies. In particular, the evidence is strongest for aspirin (approximately 50% reduction), statins (approximately 25% reduction), and metformin (approximately 50% reduction). As these drugs are generic and inexpensive, there is little incentive for the pharmaceutical industry to fund the randomized trials that would show their effectiveness definitively. We advocate that confirmation of these findings in randomized trials be considered a high research priority, as the potential impact on human lives saved could be immense.Publication Aspirin intake and breast cancer survival – a nation-wide study using prospectively recorded data in Sweden(BioMed Central, 2014) Holmes, Michelle; Olsson, Henrik; Pawitan, Yudi; Holm, Johanna; Lundholm, Cecilia; Andersson, Therese M-L; Adami, Hans-Olov; Askling, Johan; Smedby, Karin EkströmBackground: Aspirin (ASA) use has been associated with improved breast cancer survival in several prospective studies. Methods: We conducted a nested case–control study of ASA use after a breast cancer diagnosis among women using Swedish National Registries. We assessed prospectively recorded ASA exposure during several different time windows following cancer diagnosis using conditional logistic regression with breast cancer death as the main outcome. Within each six-month period of follow-up, we categorized dispensed ASA doses into three groups: 0, less than 1, and 1 or more daily doses. Results: We included 27,426 women diagnosed with breast cancer between 2005 and 2009; 1,661 died of breast cancer when followed until Dec 31, 2010. There was no association between ASA use and breast cancer death when exposure was assessed either shortly after diagnosis, or 3–12 months before the end of follow-up. Only during the period 0–6 months before the end of follow-up was ASA use at least daily compared with non-use associated with a decreased risk of breast cancer death: HR (95% CI) = 0.69 (0.56-0.86). However, in the same time-frame, those using ASA less than daily had an increased risk of breast cancer death: HR (95% CI) = 1.43 (1.09-1.87). Conclusions: Contrary to other studies, we did not find that ASA use was associated with a lower risk of death from breast cancer, except when assessed short term with no delay to death/end of follow-up, which may reflect discontinuation of ASA during terminal illness.Publication The burden of hypertension in sub-Saharan Africa: a four-country cross sectional study(BioMed Central, 2015) Guwatudde, David; Nankya-Mutyoba, Joan; Kalyesubula, Robert; Laurence, Carien; Adebamowo, Clement; Ajayi, IkeOluwapo; Bajunirwe, Francis; Njelekela, Marina; Chiwanga, Faraja S.; Reid, Todd; Volmink, Jimmy; Adami, Hans-Olov; Holmes, Michelle; Dalal, ShonaBackground: Hypertension, the leading single cause of morbidity and mortality worldwide, is a growing public health problem in sub-Saharan Africa (SSA). Few studies have estimated and compared the burden of hypertension across different SSA populations. We conducted a cross-sectional analysis of blood pressure data collected through a cohort study in four SSA countries, to estimate the prevalence of pre-hypertension, the prevalence of hypertension, and to identify the factors associated with hypertension. Methods: Participants were from five different population groups defined by occupation and degree of urbanization, including rural and peri-urban residents in Uganda, school teachers in South Africa and Tanzania, and nurses in Nigeria. We used a standardized questionnaire to collect data on demographic and behavioral characteristics, injuries, and history of diagnoses of chronic diseases and mental health. We also made physical measurements (weight, height and blood pressure), as well as biochemical measurements; which followed standardized protocols across the country sites. Modified Poison regression modelling was used to estimate prevalence ratios (PR) as measures of association between potential risk factors and hypertension. Results: The overall age-standardized prevalence of hypertension among the 1216 participants was 25.9 %. Prevalence was highest among nurses with an age-standardized prevalence (ASP) of 25.8 %, followed by school teachers (ASP = 23.2 %), peri-urban residents (ASP = 20.5 %) and lowest among rural residents (ASP = 8.7 %). Only 50.0 % of participants with hypertension were aware of their raised blood pressure. The overall age-standardized prevalence of pre-hypertension was 21.0 %. Factors found to be associated with hypertension were: population group, older age, higher body mass index, higher fasting plasma glucose level, lower level of education, and tobacco use. Conclusions: The prevalence of hypertension and pre-hypertension are high, and differ by population group defined by occupation and degree of urbanization. Only half of the populations with hypertension are aware of their hypertension, indicating a high burden of undiagnosed and un-controlled high blood pressure in these populations.Publication Feasibility of a large cohort study in sub-Saharan Africa assessed through a four-country study(Co-Action Publishing, 2015) Dalal, Shona; Holmes, Michelle; Laurence, Carien; Bajunirwe, Francis; Guwatudde, David; Njelekela, Marina; Adebamowo, Clement; Nankya-Mutyoba, Joan; Chiwanga, Faraja S.; Volmink, Jimmy; Ajayi, Ikeoluwapo; Kalyesubula, Robert; Reid, Todd G.; Dockery, Douglas; Hemenway, David; Adami, Hans-OlovBackground: Large prospective epidemiologic studies are vital in determining disease etiology and forming national health policy. Yet, such studies do not exist in sub-Saharan Africa (SSA) notwithstanding the growing burden of chronic diseases. Objective: We explored the feasibility of establishing a large-scale multicountry prospective study at five sites in four sub-Saharan countries. Design: Based on country-specific considerations of feasibility, Nigeria enrolled health care professionals, South Africa and Tanzania enrolled teachers, and Uganda enrolled village residents at one rural and one periurban site each. All sites used a 6-month follow-up period but different approaches for data collection, namely standardized questionnaires filled out by participants or face-to-face interviews. Results: We enrolled 1415 participants from five sites (range 200–489) with a median age of 41 years. Approximately half had access to clean-burning cooking fuel and 70% to piped drinking water, yet 92% had access to a mobile phone. The prevalence of chronic diseases was 49% among 45- to 54-year-olds and was dominated by hypertension (21.7% overall) – ranging from 4.5 to 31.2% across sites – and a serious injury in the past 12 months (12.4% overall). About 80% of participants indicated willingness to provide blood samples. At 6-month follow-up, 68% completed a questionnaire (45 to 96% across sites) with evidence that mobile phones were particularly useful. Conclusions: Our pilot study indicates that a large-scale prospective study in SSA is feasible, and the burden of chronic disease in SSA may already be substantial necessitating urgent etiologic research and primary prevention.Publication Urban–rural and geographic differences in overweight and obesity in four sub-Saharan African adult populations: a multi-country cross-sectional study(BioMed Central, 2016) Ajayi, IkeOluwapo O.; Adebamowo, Clement; Adami, Hans-Olov; Dalal, Shona; Diamond, Megan B.; Bajunirwe, Francis; Guwatudde, David; Njelekela, Marina; Nankya-Mutyoba, Joan; Chiwanga, Faraja S.; Volmink, Jimmy; Kalyesubula, Robert; Laurence, Carien; Reid, Todd G.; Dockery, Douglas; Hemenway, David; Spiegelman, Donna; Holmes, MichelleBackground: Overweight and obesity are on the rise in developing countries including sub-Saharan Africa. We undertook a four-country survey to show the collective burden of these health conditions as they occur currently in sub-Saharan Africa and to determine the differences between urban and rural populations and other socio-economic factors. Methods: Participants were nurses in two hospitals in Nigeria (200), school teachers in South Africa (489) and Tanzania (229), and village residents in one peri-urban (297) and one rural location in Uganda (200) who completed a standardised questionnaire. Their height and weight were measured and body mass index calculated. Factor analysis procedure (Principal component) was used to generate a wealth index. Univariate and multivariate analyses with binary logistic regression models were conducted to examine the associations between potential correlates and the prevalence of overweight and obesity with 95 % confidence intervals. Results: The prevalence of overweight and obese (combined) was 46 %, 48 %, 68 %, 75 % and 85 % in rural Uganda, peri-urban Uganda, Nigeria, Tanzania and South Africa (SA), respectively. Rural Uganda, Peri- urban Uganda, Nigeria, Tanzania and SA had obesity prevalence of 10 %, 14 %, 31 %, 40 % and 54 %, respectively (p < 0.001). Overall, prevalence of overweight was 374 (31 %) and obesity, 414 (34 %). Female sex was a predictor of overweight and obesity (combined) in peri-urban Uganda [AOR = 8.01; 95 % CI: 4.02, 15.96) and obesity in rural Uganda [AOR = 11.22; 95%CI: 2.27, 55.40), peri-urban Uganda [AOR = 27.80; 95 % CI: 7.13, 108.41) and SA [AOR = 2.17; 95 % CI: 1.19, 4.00). Increasing age was a predictor of BMI > =25 kg/m2 in Nigeria [Age > =45 - AOR = 9.11; 95 % CI: 1.72, 48.16] and SA [AOR = 6.22; 95 % CI: 2.75, 14.07], while marital status was predictor of BMI > =25 kg/m2 only in peri-urban Uganda. [Married - AOR = 4.49; 95 % CI: 1.74, 11.57]. Those in Nigeria [AOR = 2.56; 95 % CI: 1.45, 4.53], SA [AOR = 4.97; 95 % CI: 3.18, 7.78], and Tanzania [AOR = 2.68; 95 % CI: 1.60, 4.49] were more likely to have BMI > =25 kg/m2 compared with the rural and peri-urban sites. Conclusion: The high prevalence of overweight and obesity in these sub-Saharan African countries and the differentials in prevalence and risk factors further highlights the need for urgent focused intervention to stem this trend, especially among women, professionals and urban dwellers.Publication Urban and rural prevalence of diabetes and pre-diabetes and risk factors associated with diabetes in Tanzania and Uganda(Co-Action Publishing, 2016) Chiwanga, Faraja S.; Njelekela, Marina A.; Diamond, Megan B.; Bajunirwe, Francis; Guwatudde, David; Nankya-Mutyoba, Joan; Kalyesubula, Robert; Adebamowo, Clement; Ajayi, IkeOluwapo; Reid, Todd G.; Volmink, Jimmy; Laurence, Carien; Adami, Hans-Olov; Holmes, Michelle; Dalal, ShonaBackground: The increase in prevalence of diabetes and pre-diabetes in sub-Saharan Africa underlines the importance of understanding its magnitude and causes in different population groups. We analyzed data from the Africa/Harvard Partnership for Cohort Research and Training (PaCT) studies to determine the prevalence of diabetes and pre-diabetes and risk factors associated with diabetes. Methodology Participants were randomly selected from peri-urban (n=297) and rural (n=200) communities in Uganda, and teachers were recruited from schools (n=229) in urban Tanzania. We used a standardized questionnaire to collect socio-demographic and self-reported disease status including diabetes status. Blood glucose was also measured after participants fasted for 8 h. We used standard protocols for anthropometric and blood pressure measurement. Results: The overall prevalence of diabetes was 10.1% and was highest in rural Ugandan residents (16.1%) compared to teachers in Tanzania (8.3%) and peri-urban Ugandan residents (7.6%). The prevalence of pre-diabetes was 13.8%. The prevalence of self-reported diabetes was low across all sites, where 68% of participants with diabetes were not captured by self-report. In multivariable logistic regression analysis, family history (OR 2.5, 95% CI: 1.1, 5.6) and hypertension (OR 2.3, 95% CI: 1.1, 5.2) were significantly associated with diabetes. Conclusions: The prevalence of diabetes and pre-diabetes in Uganda and Tanzania is high, differs markedly between population groups, and remains undiagnosed in an alarmingly high proportion of individuals. These findings highlight the need for large-scale, prospective studies to accurately quantify the burden and identify effective intervention and treatment strategies across diverse African populations.Publication Physical activity and breast cancer survival(BioMed Central, 2009) Ogunleye, Adeyemi A; Holmes, MichellePhysical activity improves quality of life after a breast cancer diagnosis, and a beneficial effect on survival would be particularly welcome. Four observational studies have now reported decreased total mortality among physically active women with breast cancer; the two largest have also reported decreased breast cancer specific mortality. The estrogen pathway and the insulin pathway are two potential mechanisms by which physical activity could affect breast cancer survival. Randomized trials are ongoing but trials of lifestyle factors are notoriously challenging to perform. Women with breast cancer have little to lose and may possibly gain from moderate exercise.Publication Does Diet Affect Breast Cancer Risk?(BioMed Central, 2004) Holmes, Michelle; Willett, WalterThe role of specific dietary factors in breast cancer causation is not completely resolved. Results from prospective studies do not support the concept that fat intake in middle life has a major relation to breast cancer risk. However, weight gain in middle life contributes substantially to breast cancer risk. Alcohol is the best established dietary risk factor, probably by increasing endogenous estrogen levels. Hypotheses relating diet during youth to risk decades later will be difficult to test. Nevertheless, available evidence is strong that breast cancer risk can be reduced by avoiding weight gain during adult years, and by limiting alcohol consumption.