Previous Medical Histories Research Articles

Lichen planus pigmentosus-inversus following Langer's lines of cleavage: a rare clinical presentation

We present an interesting case of a patient who had a 5-month history of insidiously developing pigmented macules along skin cleavage lines over the skin of submammary and inguinal folds. There was no history of previous medication. Skin examination revealed multiple discrete and slate-grey macules distributed over the skin cleavage lines of the submammary and inguinal folds. These lesions did not coalesce, forming several, intermittent and brownish lines. Pathologically, it showed atrophic epidermis with foci of colloid bodies. A dense lymphocytic infiltration along with prominent melanophages was noticeable in the superficial dermis. The patient was diagnosed with lichen planus pigmentosus-inversus following skin cleavage lines.

Discrete Global but No Focal Gray Matter Volume Reductions in Unmedicated Adult Patients With Attention-Deficit/Hyperactivity Disorder

BackgroundGray matter reduction mainly in the anterior cingulate cortex, the basal ganglia, and the cerebellum has been reported in attention-deficit/hyperactivity disorder (ADHD). Yet, respective data remain contradictory and inconclusive. To clarify if structural alteration in these brain areas can be verified in a large cohort of adult patients and if a history of stimulant medication has an effect on brain structure, magnetic resonance imaging was performed in the context of a clinical trial on the efficacy of group psychotherapy, clinical management, methylphenidate, and placebo (Comparison of Methylphenidate and Psychotherapy in Adult ADHD Study Trial). MethodsBetween January 2007 and August 2010, 1480 patients from seven study centers across Germany, aged 18 to 58, were prescreened; 518 were assessed for eligibility; 433 were randomized; and 187 were eligible for neuroimaging. The control group included 121 healthy volunteers. Structural magnetic resonance imaging data sets were acquired. Following strict quality control, 131 patient and 95 control data sets could be analyzed. All patients were unmedicated for at least 6 months. The established method of voxel-based morphometry (VBM8 segmentation and diffeomorphic anatomical registration through exponentiated lie normalization) was used to assess global and regional brain volumes. ResultsPatients displayed subtle global cerebral volume reductions. There was no evidence of regional gray matter volume abnormalities. The inattentive ADHD subtype was linked to smaller volumes in the left dorsolateral prefrontal cortex. A history of previous medication did not modulate brain volumes. ConclusionsADHD in adulthood is associated with global rather than regional volumetric abnormalities. Previous use of stimulant medication does not seem to modify subsequent brain volumes in a significant way.

Clinical Characteristics in Lacunar Infarction with Less Than 50% Stenosis in the Parent Artery

Background: Contrary to the initial hypothesis, there is accumulating evidence that the pathogenesis of lacunar infarction (LI) is heterogeneous. LI is often accompanied by intracranial stenosis, and while the clinical significance of severe stenosis of the intracranial parent artery in LI has been demonstrated, that of mild stenosis in LI has not been. Thus the aim of this study was to determine the clinical relevance of mild intracranial stenosis in LI. Methods: Ninety-three consecutive patients with acute LI were enrolled between March 2011 and December 2013. The patients were divided according to the presence of intracranial stenosis in the parent artery into pure LI (PLI) and LI with mild intracranial stenosis (<50% stenosis, BAD). Various clinical and laboratory characteristics were compared between the two groups. Results: PLI group were older and, had a less frequent history of smoking, a larger infarct, lower likelihood of a favorable outcome, and higher National Institute of Health Stroke Scale score at discharge in the univariate analysis. After adjusting for confounding factors, BAD was associated with older age at onset [odds ratio (OR) = 1.113, 95% confidence interval (95% CI) = 1.056-1.172, p<0.001), no history of previous statin medication (OR = 13.362, 95% CI = 1.014-176.062, p=0.049), and nonsignificant stenosis in the parent artery was associated with larger infarct (β=0.296, p=0.01) in the multivariate analyses. Conclusions: LI with mild parent-artery disease was demonstrated to have distinct clinical characteristics compared to LI without parent artery disease. Thus, even mild branch atheromatous disease in LI should be evaluated thoroughly and treated via a planned and systematic approach. J Korean Neurol Assoc 33(2):82-88, 2015

Spontaneous Severe Ovarian Hyper Stimulation Syndrome Associated with Massive Pericardial Effusion and Hypothyroidism in Non-pregnant Woman.

An 18-year-old female patient presented with lump hypogastrium since one month. Lump was initially small in size but increased progressively to attain the present size. She also complained of non-specific, non-localized abdominal pain which was chronic, dull aching in nature, and nonradiating. It was mild in severity with no aggravating or relieving factors. Bladder and bowel habits were normal. She had an irregular menstrual cycle of 30–60 days, 1–2 days duration and scanty flow. She had no history of previous medication or hospitalization. On examination, two discrete tender lumps, 7–9 cm in size and firm in consistency, and well-defined margins present in hypogastrium. Per vaginal examination could not be performed due to denial of consent due to virgin status. All laboratory investigations were within normal limit except hemoglobin which was 5.9 mg% and low T3 0.10 ng/ml (normal 0.7–2.0 ng/ml), low T4 1.2 lg/dl (normal 5.5–13.5 lg/dl), and high TSH 102 llu/ml (normal 0.3–5.0 llu/ml) levels. CA 125 and other tumor markers were within normal limits. Ultrasonography at the time of admission showed bilateral enlarged ovaries of size 15.22 9 8.26 cm(Rt. Ovary) and 11.82 9 6.24 cm (Lt. ovary) with multiple cysts of varying sizes in both ovaries, giving a classical ‘spoke wheel-like appearance.’ A diagnosis of bilateral ovarian cysts was made, and diagnostic laparoscopy was planned for further management. On pre-anesthetic cardiopulmonary evaluation, pericardial effusion was suspected. Hence, cardiology opinion was taken and subsequent echocardiogram revealed massive pericardial effusion. Then, on the basis of previous findings and echocardiogram put together, a diagnosis of spontaneous Singh A. (&), Senior Resident Singh K., Ex.Senior professor and Head Of Department Khandelwal R. G., Assistant Professor Choudhary P., Post Graduate Student Sharma V. K., Post Graduate Student Department of Surgery, J. L. N. Medical College, Ajmer 305001, India e-mail: dr.amit5280@gmail.com Dr. Amit Singh completed his M.B.B.S from Dr Sampurnanand Medical College, Jodhpur, 2005, and M.S in general surgery from Jawaharlal Nehru Medical College, Ajmer, 2011. Presently, he is Senior Resident at Jawahar Lal Nehru medical college, Ajmer. His keen area of interest is hepatobiliary and gastrointestinal surgery. He has many international and national publications. The Journal of Obstetrics and Gynecology of India (March–April 2015) 65(2):132–135

Periodontal disease and systemic diseases in an older population

ObjectiveTo evaluate the relationship between older adults’ medical and oral conditions and their self-reports of periodontal conditions with clinically obtained data. BackgroundConcerns about oral health of elders and its association with systemic diseases have been gaining more attention. MethodsA total of 201 older subjects were interviewed about their previous medical and dental histories and were asked to complete a health questionnaire. Each subject received full mouth exam, including counting number of natural teeth remaining, gingival (GI) and plaque index (PI), CPITN and denture status. ResultsElders who completed health questionnaires had mean age of 62.5. Mean CPITN score was 1.62(±1.12), PI was 1.57(±1.48), and GI was 1.55(±1.31). Women had higher prevalence of CVD and osteoporosis than men (p=0.008, p=0.0001, respectively). Subjects who reported bleeding upon brushing had higher PI and GI scores (p=0.03, p=0.05, respectively). Smokers were more likely to describe their periodontal tissues as unhealthy (72.3% vs. 27.7%, p=0.01), whereas self-reports of healthy vs. unhealthy gums did not differ between non-smokers. ConclusionThese findings suggest that a number of systemic conditions are associated with indicators of periodontal disease, and self-reports of oral conditions are independent of systemic diseases.

Risk factors for suicidal behaviour in individuals on disability pension due to common mental disorders - a nationwide register-based prospective cohort study in Sweden.

BackgroundCommon mental disorders (CMD) have become one of the leading causes for disability pension (DP). Studies on predictors of adverse health outcome following DP are sparse. This study aimed to examine the association of different socio-demographic factors and health care consumption with subsequent suicidal behaviour among individuals on DP due to CMD.MethodThis is a population-based prospective cohort study based on register data. All individuals aged 18–64 years, living in Sweden on 31-Dec-2004 who in 2005 were on DP due to CMD (N = 46 745) were followed regarding suicide attempt and suicide (2006–10). Univariate and multivariate hazard ratios (HR) and 95% confidence intervals (CI) for suicidal behaviour were estimated by Cox regression.ResultsDuring the five-year follow-up, 1 046 (2.2%) and 210 (0.4%) individuals attempted and committed suicide, respectively. Multivariate analyses showed that young age (18–24 years) and low education predicted suicide attempt, while living alone was associated with both higher suicide attempt and suicide (range of HRs 1.23 to 1.68). Combined prescription of antidepressants with anxiolytics during 2005 and inpatient care due to mental diagnoses or suicide attempt (2001–05) were strongly associated with suicide attempt and suicide (range of HRs 1.3 to 4.9), while inpatient care due to somatic diagnoses and specialized outpatient care due to mental diagnoses during 2001–05 only predicted suicide attempt (HR 1.45; 95% CI: 1.3–1.7; HR 1.30; 95% CI: 1.1–1.7).ConclusionsAlong with socio-demographic factors, it is very important to consider type of previous healthcare use and medication history when designing further research or intervention aiming at individuals on DP due to CMD. Further research is warranted to investigate both characteristics of disability pension due to CMD, like duration, diagnoses and grade as well as mechanisms to subsequent suicidal behavior, taking potential gender differences into consideration.

Surgery for ingrowing nail is an effective treatment choice in an urban region

Objectives: The aim of this study is to evaluate the risk factors and treatment outcomes of patients with ingrowing nails in an urban region. Methods: This descriptive prospective study was performed in a General Surgery outpatient clinic in an urban region for 6 months. The data about sex, risk factors, age, history of previous medication were obtained. Body mass index, the ratio of second toe to the length of hallux, the ratio of the diameter of hallux to width of hallux nail were calculated. The ingrowing nails with stage II and III were treated by Winograd method. The patients were followed for recurrences and complications for nearly 6 months. Results: Total 61 patients were treated. Female to male ratio was 33/28. The man age was 24.8±11.8. The mean BMI was 28.5±5.3. Tight shoes, improper nail trimming were the leading etiological factors. Total 44 patients had a history of at least one time antibiotic usage history. Symptoms were found to be increased after pregnancy (66.7%). Lateral localization was significantly higher in patients with longer second toe than the hallux. There were 5 postoperative infections (8.2%) and only one (1.6%) recurrence. Conclusion: Ingrowing nail is an important problem because of increased risk factors in urban region. Winograd method which is an easy method with low recurrence and high patient satisfaction can be preferred.

CANCER DE LA THYROIDE CHEZ L'ENFANT

We report here a study of 7 cases of thyroid cancer in child. This study that we reinforced by litterature review aims to point out the different aspects of this affection : clinical features, the complementary examinations and the management to diagnose it with certainly and lastly, the different therapeutical attitudes. It is question of 7 children between 8 and 15 years aged, with a female prevalence, without peticuliar previous medical histories. Clinically, these childrens present an euthyroidal goitre, cervical adenopathies with conservation of good general health conditions. Scintigraphy showed a cold nodul that was proved to the neoplasic at the anatomo-pathological study, it was papillar or papillo-vesicular carcinoma. The surgical management has at the present time a tendancy to conservative surgery combined or not with a gonglionic curage, followed by a substitute hormonal treatment. In general, the prognostic of this affection is good for the differenciated forms whereas it remains has for anaplasic non differenciated forms.

Unrecognized acute lithium toxicity: a case report

Abstract We report a case of a 63-year-old male who has been admitted to the Emergency department with nonspecific symptoms. Lithium toxicity was not at first recognized. When we obtained sufficient information about previous medication and medical history, we measured lithium levels found to be 1.46 mmol/L. Although the value of lithium was mildly elevated, nephrotoxicity was produced leading to severe renal insufficiency and neurological symptoms. Hemodialysis was started, and we succeed to treat the patient without squeals. This case illustrates some of the factors that lead to lithium toxicity as well as the need to consider lithium toxicity to the differential diagnosis of a patient presenting with renal insufficiency with or without change in mental status and neurologic symptom.

Abstract 3305: Intensive Lipid-lowering and Early Functional Outcome in Acute Ischemic Stroke: Propensity Score Matching Analysis

Background This retrospective case-control study was designed to compare the effect of early high-dose atorvastatin treatment on early functional outcome in acute ischemic stroke patients using propensity score matching (PSM). Study design and population Acute ischemic stroke patients were selected from prospectively collected hospital-based stroke registry. Because the purpose of this study was comparing two treatment strategies for statin treatment, patients with cardioembolic stroke subtype or other-etiology were excluded. Patients were allocated into two groups: Intensive treatment group (atorvastatin 80mg; IT) and conventional treatment group (atorvastatin 10-40mg or other lipid-lowering agent; CT). All the patients were prescribed for aspirin 300mg at admission except for the patients who were considered for thrombolysis. After admission, the patients were prescribed for antithrombotics according to the clinical decision of the attending physician. All other practice guidelines except management of dyslipidemia were followed for previously published guidelines for management of stroke patients. Detailed demographic factors, vascular risk factors, laboratory parameters and vascular imaging were recorded. The end points were composed of two parameters. First, early neurological deterioration (END) defined as 4 points or more deterioration of National Institute of Health Stroke Score (NIHSS) from admission to the seventh hospital day. In case of discharge before the seventh hospital day, NIHSS at discharge was substituted for that of the seventh hospital day. Second, favorable outcome was defined as 0-2 of modified Rankin Score (mRS) measured at 3 months from the onset of stroke. Because baseline characteristics between the groups was supposed to be different, propensity score matching was performed to adjust for potential selection biases and confounding. A logistic regression model was fitted relating treatment strategies (IT and CT) to pretreatment patient characteristics. For the comparison between IT and CT in terms of END and favorable outcome, McNemar test were performed. Results: Among the study population, data of 178 patients for IT and 218 patients for CT were collected. Between the groups, history of previous stroke, TOAST classification, and previous medication of clopidogrel showed significant difference. There was no significant difference of 90-day favorable outcome and END. After PSM, 116 patients for each group were selected. There was no significant difference of baseline characteristics between the groups after PSM. There was no significant difference between IT and CT in terms of 90-day favorable outcome (75.3% in IT and 78.4% in CT, p = 0.457) and END (IT 72.3%, CT 78.6%, p = 0.097). Conclusion In this study, effect of intensive lipid-lowering treatment in acute stroke patients was negligible in terms of early functional outcome.

Exploring and Exploiting Disease Interactions from Multi-Relational Gene and Phenotype Networks

The availability of electronic health care records is unlocking the potential for novel studies on understanding and modeling disease co-morbidities based on both phenotypic and genetic data. Moreover, the insurgence of increasingly reliable phenotypic data can aid further studies on investigating the potential genetic links among diseases. The goal is to create a feedback loop where computational tools guide and facilitate research, leading to improved biological knowledge and clinical standards, which in turn should generate better data. We build and analyze disease interaction networks based on data collected from previous genetic association studies and patient medical histories, spanning over 12 years, acquired from a regional hospital. By exploring both individual and combined interactions among these two levels of disease data, we provide novel insight into the interplay between genetics and clinical realities. Our results show a marked difference between the well defined structure of genetic relationships and the chaotic co-morbidity network, but also highlight clear interdependencies. We demonstrate the power of these dependencies by proposing a novel multi-relational link prediction method, showing that disease co-morbidity can enhance our currently limited knowledge of genetic association. Furthermore, our methods for integrated networks of diverse data are widely applicable and can provide novel advances for many problems in systems biology and personalized medicine.

When Patients Report Diseases That Prescribers Seem Unaware of: Discordance Between Patient and Physician Reporting of Risk-Related Previous History in NSAID Users From the CADEUS Study

Prescribers are often unaware of possibly dangerous previous medical histories (PMHs) of their patients. Data from a study of nonsteroidal anti-inflammatory drug (NSAID) users served to identify factors associated with this lack of awareness. In this study, we analyzed the factors that may have led prescribers to report the absence of some PMHs that the patients reported as being present. Of 26,618 patients prescribed an NSAID, 469 (1.7%) reported a PMH of unstable angina, 648 (2.4%) reported heart failure, 2,244 (8.4%) reported gastric or duodenal ulcer, 489 (1.8%) reported upper gastrointestinal tract bleeding (UGIB), 5,343 (20.0%) reported gastroesophageal reflux disease (GERD), and 7,832 (29.4%) reported dyspepsia. Between 64 (GERD) and 92% (UGIB) of these patient-reported PMHs were absent in the corresponding prescribers' reports. This discordance was associated with the following factors: patients of younger age, female patients, less frequent patient-prescriber contact, prescription of NSAID by a specialist, no recent specialist consultation, hospitalization or surgery related to the PMH, and no dispensation of proton-pump inhibitors (PPIs) for digestive disorder-related PMHs. The study showed that a substantial proportion of prescribers seemed unaware of the presence of risk-related PMHs that the patient reported when asked.

A Lung Mass Causing Cardiovascular Impairment

A Lung Mass Causing Cardiovascular Impairment

Management of hypertension in the elderly patient

Hypertension in the elderly is associated with increased occurrence rates of sodium sensitivity, isolated systolic hypertension, and 'white coat effect'. Arterial stiffness and endothelial dysfunction also increase with age. These factors should be considered in selecting antihypertensive therapy. The prime objective of this therapy is to prevent stroke. The findings of controlled trials show that there should be no cut-off age for treatment. A holistic program for controlling cardiovascular risks should be fully discussed with the patient, including evaluation to exclude underlying causes of secondary hypertension, and implementation of lifestyle measures. The choice of antihypertensive drug therapy is influenced by concomitant disease and previous medication history, but will typically include a thiazide diuretic as the first-line agent; to this will be added an angiotensin inhibitor and/or a calcium channel blocker. Beta blockers are not generally recommended, in part because they do not combat the effects of increased arterial stiffness. The hypertension-hypotension syndrome requires case-specific management. Drug-resistant hypertension is important to differentiate from faulty compliance with medication. Patients resistant to third-line drug therapy may benefit from treatment with extended-release isosorbide mononitrate. A trial of spironolactone may also be worthwhile.

Mycobacterium xenopi: Evidence for Increased Rate of Clinical Isolation

In light of recent reports of increased isolation of M. xenopi, we reviewed the number of M. xenopi isolates in a hospital setting over five years. A total of 133 isolates from 100 patients were reported, of these isolates, 8 were reported over the first two years, 21 isolates in the third year, 47 isolates in year four and 57 isolates in year five. The specimen sources were mainly respiratory specimens; however a few specimens were isolated from other sources. Clinical data on 12 patients with repeated isolates are presented. Patient conditions upon admission and previous medical histories are shown and compared to earlier reports. An increased awareness of the presence of this organism is necessary since the clinical presentation of patients with M. xenopi can be confused with tuberculosis.

Recurrent croup presentation, diagnosis, and management

Purpose The lack of clinical insight into recurrent croup often leads to underdiagnosis of an upper airway lesion, and subsequently, inadequate treatment. This study examined the underlying etiology, diagnosis, treatment, and clinical outcome of patients with a history of recurrent croup identified at initial presentation. The aim was to present common diagnostic features and suggest new diagnostic and management recommendations. Materials and methods A retrospective chart review of 17 children diagnosed with recurrent croup. Demographic, historical, and intraoperative data as noted in clinic charts were collected. Specific collected data included age, sex, chief complaint, presenting symptoms, past medical history, previous medication history, number of emergency room visits and inpatient admissions, tests/procedures performed and corresponding findings, current treatment given, and posttreatment clinical outcome. Results Six (35.3%) patients presented initially with a past medical history of gastroesophageal reflux disease. Fourteen (82.3%) patients had positive endoscopic evidence of gastroesophageal reflux. For these 14 patients, 44 laryngopharyngeal reflux lesions were noted, with 32 (72.7%) occurring in the subglottis. All 14 patients demonstrated various degrees of subglottic stenosis ranging from 30% to 70% (Cotton-Myer grade I-II). All 17 patients (100%) demonstrated subglottic stenosis ranging from 15% to 70% airway narrowing. Conclusions History suggestive of recurrent croup requires close monitoring and expedient direct laryngoscopy/bronchoscopy for diagnosis. Long-term follow-up and antireflux treatment are necessary as well as endoscopic documentation of significant reflux resolution.

Weight change in the acute treatment of bipolar I disorder: A naturalistic observational study of psychiatric inpatients

Background Bipolar patients have increased prevalence rates of overweight and obesity compared with the general population. Recent increases in the use of atypical antipsychotics and combination therapies have led to growing concern about obesity and metabolic disturbances. We therefore evaluated weight change and its correlates during the treatment of acute mania in a closed-ward hospital setting. Methods We evaluated weight change over 4 weeks in 179 consecutive patients with bipolar I disorder presenting with acute manic symptoms. Results Overall weight change was + 2.7 ± 3.0 kg (+ 4.6 ± 5.2%). Whereas 24.6% of patients were obese at baseline, 36.3% were obese after 4 weeks. Duration of illness was correlated with weight change, but its effect was not robust. Baseline weight/BMI, sex, age of onset, and history of previous medication were not significantly correlated with weight changes. Patients prescribed olanzapine plus valproate showed the largest increase in weight (3.8 ± 2.9 kg). Overall, patients on any kind of atypical antipsychotics showed greater weight gain than those on typical antipsychotics or without antipsychotics. Combination treatment with antipsychotics and mood stabilizer resulted in greater weight gain than monotherapy with an antipsychotic or mood stabilizer. Limitations The short-term assessment (4 weeks) of weight change and the lack of variables previously reported to be related to weight gain, such as number of depressive episodes, warrant caution in the interpretation of our results. Conclusions Even during short period of acute treatment, bipolar patients showed significant weight gain and became obese in a closed-ward setting. Clinicians prescribing combination therapies should pay more attention to weight gain and obesity.

Interictal Psychosis After Stroke With Forced Normalization

Interictal Psychosis After Stroke With Forced Normalization

Determinants of Compliance with Colonoscopy in Patients with Adenomatous Colon Polyps

Purpose: Removal of adenomas with at least a three to five-year follow up reduces incidence of colorectal cancer. The aim of this study was to determine factors which affect compliance of a follow up colonoscopy in patients with previously diagnosed adenomatous colon polyps. Methods: A retrospective review was performed on patients with adenomatous polyps excised between July to December 1998. The hospital endoscopy database was used to determine whether these patients were compliant with their follow-up colonoscopy. 34 clinical factors were assessed by univariate analysis in patients grouped into whether they were compliant (n = 60) or non-compliant (n = 59). Factors assessed included demographics, compliance with previous healthcare visits, substance abuse, mental illness, travel distance, and medication history. Significant variables by univariate analysis were included in a multivariate regression analysis model to determine factors predicting early mortality. All values are presented as means ± SE, statistic significance was a p≤ 0.05. Results: 119 patients with adenomatous polyps were identified. They were all men (mean age 64.2 yrs). 114/119 (96%) had a documented recommendation for follow up of 5 years or less. 40% (34/119) had previously undergone colonoscopy and 58% (49 of 119) were symptomatic at the time of the colonoscopy. 8% (7/119) had a family history of colorectal cancer. Follow up was available in all 119 of these cases, 60 (50.4%) of which had been compliant with follow up colonoscopy. In a univariate analysis, greater number of polyps (p= 0.04), presence of diabetes (p= 0.003), NSAIDs use (p= 0.02), HMG Co-A reductase use (p= 0.005), first-degree relatives with colon cancer (p= 0.05) and compliance with outpatient clinic follow-up (p < 0.001) were significantly associated with patient compliance with follow up colonoscopy. A multivariate logistics regression analysis revealed HMG Co-A reductase use (p= 0.05) first-degree relatives with colon cancer (p= 0.05) and compliance with outpatient clinic follow-up (p < 0.001) to be independently associated with compliance. Conclusions: Age, substance abuse, mental illness, or travel distance was not associated with compliance with follow-up colonoscopy. Use of HMG Co-A reductase and having a 1st degree relative with colon cancer are independent predictors of compliance. The strongest predictor with noncompliance can be predicted from noncompliance with other healthcare encounters.

Aspirin Resistance

Recent studies have described the incidence (approximately one in eight high-risk patients will experience a further atherothrombotic event over a 2-year period) of aspirin (acetylsalicylic acid) resistance and its possible background. The aim of this study was to compare the characteristics (risk profile, previous diseases, medications and haemorrheological variables) of patients in whom aspirin provided effective platelet inhibition with those in whom aspirin was not effective in providing platelet inhibition. 599 patients with chronic cardio- and cerebrovascular diseases (355 men, mean age 64 +/- 11 years; 244 women, mean age 63 +/- 10 years) taking aspirin 100-325 mg/day were included in the study. Blood was collected between 8:00am and 9:00am from these patients after an overnight fast. The cardiovascular risk profiles, history of previous diseases, medication history and haemorrheological parameters of patients who responded to aspirin and those who did not were compared. Platelet and red blood cell (RBC) aggregation were measured by aggregometry, haematocrit by a microhaematocrit centrifuge, and plasma fibrinogen by Clauss' method. Plasma and whole blood viscosities were measured using a capillary viscosimeter. Compared with aspirin-resistant patients, patients who demonstrated effective aspirin inhibition had a significantly lower plasma fibrinogen level (3.3 g/L vs 3.8 g/L; p < 0.05) and significantly lower RBC aggregation values (24.3 vs 28.2; p < 0.01). In addition, significantly more patients with effective aspirin inhibition were hypertensive (80% vs 62%; p < 0.05). Patients who had effective platelet aggregation were significantly more likely to be taking beta-adrenoceptor antagonists (75% vs 55%; p < 0.05) and ACE inhibitors (70% vs 50%; p < 0.05), whereas patients with ineffective platelet aggregation were significantly more likely to be taking HMG-CoA reductase inhibitors (statins) [52% vs 38%; p < 0.05]. Use of statins remained an independent predictor of aspirin resistance even after adjustment for risk factors and medication use (odds ratio 5.92; 95% CI 1.83, 16.9; p < 0.001). The mechanisms underlying aspirin resistance are multifactorial. Higher fibrinogen concentrations increase RBC aggregation and can also result in increased platelet aggregation. The higher rate of hypertension in patients with effective platelet aggregation on aspirin could explain the differences in beta-adrenoceptor antagonist and ACE inhibitor use between these patients and aspirin-resistant patients. Furthermore, an additive effect of these drugs may contribute to effective antiplatelet therapy. It is also possible that drug interactions with statins might reduce aspirin bioavailability and/or activity, thereby reducing platelet inhibition in aspirin-resistant patients.