Original Article

Wong JE, Poh BK, Nik Shanita, S, Izham MM, Chan KQ, Tai MD, Ng WW, Ismail MN
Correspondence: Prof Dr Poh Bee Kun, pbkoon@fskb.ukm.my
 

ABSTRACT
Introduction This study aimed to measure the basal metabolic rate (BMR) of elite athletes and develop a genderspecific predictive equation to estimate their energy requirements.
Methods 92 men and 33 women (aged 18–31 years) from 15 sports, who had been training six hours daily for at least one year, were included in the study. Body composition was measured using the bioimpedance technique, and BMR by indirect calorimetry. The differences between measured and estimated BMR using various predictive equations were calculated. The novel equation derived from stepwise multiple regression was evaluated using Bland and Altman analysis.
Results The predictive equations of Cunningham and the Food and Agriculture Organization/World Health Organization/United Nations University either over- or underestimated the measured BMR by up to ± 6%, while the equations of Ismail et al, developed from the local non-athletic population, underestimated the measured BMR by 14%. The novel predictive equation for the BMR of athletes was BMR (kcal/day) = 669 + 13 (weight in kg) + 192 (gender: 1 for men and 0 for women) (R2 0.548; standard error of estimates 163 kcal). Predicted BMRs of elite athletes by this equation were within 1.2% ± 9.5% of the measured BMR values.
Conclusion The novel predictive equation presented in this study can be used to calculate BMR for adult Malaysian elite athletes. Further studies may be required to validate its predictive capabilities for other sports, nationalities and age groups.

Keywords: athletes, basal metabolic rate, body composition, energy requirement, predictive equation
Singapore Med J 2012; 53(11): 744–749

Orguc S, Basara I, Coskun T
Correspondence: Dr Isil Basara, slbasara@hotmail.com
 

ABSTRACT
Introduction The specificity of conventional magnetic resonance (MR) imaging is lower than its high sensitivity. Diffusion-weighted imaging (DWI), based on alterations in the microscopic motion of water molecules, promises improved specificity for breast MR imaging. In this study, we aimed to determine the diagnostic potential of DWI to differentiate between benign and malignant breast lesions and normal breast tissue.
Methods Dynamic contrast-enhanced breast MR imaging and DWI were applied to 108 women. Apparent diffusion coefficient (ADC) values were obtained for normal breast tissue (n = 183), benign lesions (n = 66) and malignant lesions (n = 58). The results were compared with the patients’ final diagnoses.
Results Mean ADC values for benign and malignant breast lesions were 1.04 × 10−3 ± 0.29 × 10−3 mm2/s and 2.00 × 10−3 ± 0.55 × 10−3 mm2/s, respectively (p = 0.001, Student’s t-test), while that for normal breast tissue was 1.78 × 10−3 ± 0.33 × 10−3 mm2/s. With a cut-off value of 1.46 × 10−3 mm2/s for ADC in receiver operating characteristic analysis, 95% sensitivity and 85% specificity were achieved for differentiating between benign and malignant lesions.
Conclusion DWI of the breast can help differentiate benign and malignant breast lesions from normal breast tissue. DWI, which can be easily introduced into standard breast MR imaging protocols without increasing imaging times,promises to increase the accuracy of breast MR imaging without contrast media. However, its clinical value will depend on the standardisation of b-values and other technical parameters in larger future study series.

Keywords: apparent diffusion coefficient, breast cancer, breast tumour, diffusion-weighted imaging, magnetic resonance imaging
Singapore Med J 2012; 53(11): 737–743

Lim BK, Bux SI, Rahmat K, Lam SY, Liew YW
Correspondence: Dr Lim Bee Kuan, beekuan76@hotmail.com
 

ABSTRACT
Introduction We compared the effectiveness of different types of non-commercial neutral oral contrast agents for bowel distension and mural visualisation in computed tomographic (CT) enterography.
Methods 90 consecutive patients from a group of 108 were randomly assigned to receive water (n = 30), 3.8% milk (n = 30) or 0.1% gastrografin (n = 30) as oral contrast agent. The results were independently reviewed by two  radiologists who were blinded to the contrast agents used. The degree of bowel distension was qualitatively scored on a four-point scale. The discrimination of bowel loops, mural visualisation and visualisation of mucosal folds were evaluated on a ‘yes’ or ‘no’ basis. Side effects of the various agents were also recorded.
Results 3.8% milk was significantly superior to water for bowel distension (jejunum, ileum and terminal ileum), discrimination of bowel loops (jejunum and ileum), mural visualisation and visualisation of mucosal folds (ileum and terminal ileum). It was also significantly superior to 0.1% gastrografin for bowel distension, discrimination of bowel loops, mural visualisation and visualisation of mucosal folds (jejunum, ileum and terminal ileum). However, 10% of patients who received 3.8% milk reported immediate post-test diarrhoea. No side effects were documented for patients who received water and 0.1% gastrografin.
Conclusion 3.8% milk is an effective and superior neutral oral contrast agent for the assessment of the jejunum, ileum and terminal ileum in CT enterography. However, further studies are needed to explore other suitable oral contrast agents for CT enterography in lactose- or cow’s milk-intolerant patients.

Keywords: bowel distension, CT enterography, imaging, mural visualisation, neutral oral contrast
Singapore Med J 2012; 53(11): 732–736

Iwalokun BA, Iwalokun SO, Hodonu SO, Aina OA, Omilabu S
Correspondence: Dr Iwalokun A Bamidele, bamwal@yahoo.com
 

ABSTRACT
Introduction Microbial burden involving parvovirus B19 infection has been recognised as a major cause of morbidity and mortality in sickle cell anaemia (SCA) patients. Given the recent reports of parvovirus B19 infection in Nigeria and the role of inflammation in sickle cell crisis, knowledge of the relationship between the two may be essential for deploying appropriate interventions in infected patients. This study determined the serum levels of tumour necrosis factor alpha (TNF-α) and C-reactive protein (CRP) as inflammatory markers in Nigerian SCA patients with and without parvovirus B19 infections.
Methods A total of 64 SCA patients aged 5–25 years and 41 age-matched apparently healthy volunteers with haemoglobin genotypes AA or AS were enrolled with consent into the study. Parvovirus B19 infection and serum levels of TNF-α and CRP were determined by the ELISA method.
Results The overall prevalence rate of parvovirus B19 infection in the study subjects was 13.3%. This rate further showed gender variation and negative correlation with age. Significant (p < 0.05) increases in serum CRP and TNF-α levels, with further elevation in unsteady state SCA patients, were observed in comparison with the control. Unlike the control, 29.6% and 21.9% of the SCA patients elicited TNF-α and CRP above threshold levels, respectively. Parvovirus B19 infection was found to elicit greater increases in these inflammatory markers than in infected non-SCA controls.
Conclusion We conclude that parvovirus B19 infection is common in this environment, and that serum TNF-α and CRP are predictors of clinical inflammatory episodes in infected SCA patients.

Keywords: inflammation, Lagos, Nigeria, parvovirus B19, sickle cell anaemia
Singapore Med J 2012; 53(11): 726–731

Poon LM, Jin J, Chee YL, Ding Y, Lee YM, Chng WJ, Chai LY, Tan LK, Hsu LY
Correspondence: Dr Hsu li Yang, mdchly@nus.edu.sg
 

ABSTRACT
Introduction Institutional febrile neutropenia (FN) management protocols were changed following the finding of a high prevalence of ceftazidime-resistant Gram-negative bacteraemia (CR-GNB) among haematology patients with FN. Piperacillin/tazobactam replaced ceftazidime as the initial empirical antibiotic of choice, whereas carbapenems were prescribed empirically for patients with recent extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae colonisation/infection. An audit was conducted to determine the impact of these changes.
Methods Data from all FN episodes between October 2008 and December 2010 were collected prospectively, with mid-November 2009 demarking the transition between pre-intervention and intervention periods. Outcomes measured included 30-day mortality post-development of FN and the presence of CR-GNB.
Results There were 427 FN episodes (200 in the pre-intervention period) from 225 patients. The prevalence of CRGNB was 10.3%, while the 30-day mortality was 4.7%, with no difference between pre-intervention and intervention periods. Independent risk factors for 30-day mortality included the presence of active haematological disease, vancomycin prescription and older age. Independent factors associated with initial CR-GNB were profound neutropenia, the presence of severe sepsis and active haematological disease. Recent ESBL-producing Enterobacteriaceae colonisation/infection was not predictive of subsequent CR-GNB (positive predictive value 17.3%), whereas a model based on independent risk factors had better negative predictive value (95.4%) but similarly poor positive predictive value (21.4%), despite higher sensitivity.
Conclusion A change in the FN protocol did not result in improved outcomes. Nonetheless, the audit highlighted that empirical carbapenem prescription may be unnecessary in FN episodes without evidence of severe sepsis or septic shock, regardless of previous microbiology results.

Keywords: antimicrobial drug resistance, empirical antibiotics, febrile neutropenia, Gram-negative bacteraemia, mortality
Singapore Med J 2012; 53(11): 720–725

Bhargava M, Cheung CY, Sabanayagam C, Kawasaki R, Harper CA, Lamoureux EL, Chow WL, Ee A, Hamzah H, Ho M, Wong W, Wong TY
Correspondence: Prof Wong Tien Yin, ophwty@nus.edu.sg
 

ABSTRACT
Introduction We compared the agreement of diabetic retinopathy (DR) assessment between trained non-physician graders (NPGs) and family physicians (FPs) in a primary healthcare setting.
Methods This was a cross-sectional study conducted retrospectively over a period of one month. The participants were diabetic patients from two primary healthcare clinics (polyclinics) in Singapore. Single-field digital retinal images were obtained using a non-mydriatic 45-degree fundus camera. Retinal images were graded for the presence or absence of DR by FPs at the polyclinics and by NPGs at a central ocular grading centre. The FPs’ and NPGs’ assessments of DR were compared with readings by a single retinal specialist (reference standard).
Results A total of 367 diabetic patients (706 eyes) were included in the study. The mean age of the patients was 63 years, and the majority were Chinese (83.8%). For DR assessment, the agreement between NPGs and the retinal specialist was substantial (? = 0.66), while the agreement between FPs and the retinal specialist was only fair (? = 0.40). NPGs’ assessment showed higher sensitivity (70% vs. 45%) and comparable specificity (94% vs. 92%) as compared to FPs’ assessment. The area under the receiver operating characteristic curve of NPGs’ assessment of DR was greater than that of the FPs’ (0.82 vs. 0.69, p < 0.001).
Conclusion This study has demonstrated that trained NPGs are able to provide good detection of DR and maculopathy from fundus photographs. Our findings suggest that DR screening by trained NPGs may provide a cost-effective alternative to FPs.

Keywords: diabetic retinopathy, family physicians, screening, single-field digital retinal images, trained graders
Singapore Med J 2012; 53(11): 715–719

Zolala F, Heidari F, Afshar N, Haghdoost AA
Correspondence: Dr Ali Akbar Haghdoost, ahaghdoost@kmu.ac.ir

ABSTRACT
Introduction Maternal mortality is a tragic death, and is perceived as a sensitive indicator of the socioeconomic status and healthcare services in a given country. In this study, the relationship between maternal deaths and factors such as socioeconomic development and the proportion of medical professionals in Iran was examined.
Methods This was an ecological study, where three main groups of data based on different provinces were applied. Data included maternal mortality ratio, the proportion of medical professionals and socioeconomic variables, such as urban residency, unemployment and literacy. Data were obtained from various sources, including census returns, the Family Unit at the Ministry of Health and Medical Education, Tehran and the Iran Medical Council. Data were analysed using univariate and multivariate methodologies.
Results Multivariate analysis showed a significant inverse relationship between maternal deaths and variables of male literacy (p < 0.001) and unemployment (p = 0.04). A marginally significant association was also found between maternal deaths and the proportion of midwives (p = 0.09).
Conclusion Our findings underscore the role of literacy, particularly male literacy, in the prevention of maternal deaths. Iran, as a male-dominated society, could benefit from targeting men for training programmes to enhance the health of their families, and ultimately, that of the society. As economic status does play a role in maternal deaths, there is a need to strengthen the financial situation of families. The number of skilled medical personnel available in a population also plays a key role in reducing maternal deaths.

Keywords: literacy, maternal mortality, women’s status
Singapore Med J 2012; 53(10): 684–689

Ab Hamid J, Mohtarrudin N, Osman M, Andi Asri AA, Wan Hassan WH, Aziz R
Correspondence: Mr Jabrullah Ab Hamid, jabrullah.abh@gmail.com

ABSTRACT
Introduction Gestational hypertension (GH) is a common disorder during pregnancy that can progress to preeclampsia and cause various subsequent fatal complications. A cluster of enzymes, called matrix metalloproteinases (MMPs), and its specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs), have been reported to be involved in the pathophysiology of GH. The purpose of this study was to examine circulating levels of MMP-9, TIMP-1 and TIMP-2 in pregnant women who had GH and those who were normotensive.
Methods In a case-control study, the total levels of MMP-9, TIMP-1 and TIMP-2 in the sera of 108 pregnant patients were evaluated using enzyme-linked immunosorbent assays. 54 patients with GH (test group) and 64 normotensive pregnant women (control group) were included in the study.
Results While MMP-9 levels showed a high level of expression in the GH group (p = 0.085), TIMP-1 and TIMP-2 levels showed low levels of expression for the same. Weak positive correlations were found on correlation analysis between maternal age and TIMP-1 in the GH group (r = 0.278, p < 0.05), and between gestational age and TIMP-2 in the control group (r = 0.318, p < 0.05).
Conclusion Our findings suggest that MMP-9 may be involved in the pathophysiology of GH. It may be of value to further evaluate MMP-9 as a potential biomarker for predicting preeclampsia in pregnant women.

Keywords: biomarker, case-control, gestational hypertension, matrix metalloproteinase, tissue inhibitor of metalloproteinase
Singapore Med J 2012; 53(10): 681–683

Mandal D, Dattaray C, Sarkar R, Mandal S, Choudhary A, Maity TK
Correspondence: Dr Debasmita Mandal, drdebasmitamondal@yahoo.com

ABSTRACT
Introduction We aimed to analyse the pregnancy outcome of women with extrahepatic portal vein obstruction.
Methods This was a retrospective observational analysis conducted at the Institute of Postgraduate Medical Education and Research, Kolkata, India, between January 2007 and September 2009. A total of 41 pregnancies in 24 women were evaluated.
Results All women conceived spontaneously (maternal age 20–35 years). 17 women had moderate-to-severe anaemia, and five women had pancytopenia. Variceal bleeding occurred in ten women during pregnancy, which was managed successfully with endoscopic sclerotherapy in eight women and endoscopic variceal ligation in two women. Preterm labour (14.63%), postpartum haemorrhage (7.31%), abortion (4.87%) and pregnancy-induced hypertension (4.87%) were observed in the 41 pregnancies. There were 39 live births and almost all mothers delivered vaginally, except for four who underwent Caesarean section for obstetric indications. Prematurity (15.38%), low birth weight (10.25%), admission to the neonatal intensive care unit (12.82%), stillbirth (2.56%) and neonatal death (2.56%) were noted in the newborns.
Conclusion Variceal bleeding during pregnancy coincided with unfavourable outcomes. Although endoscopic obliteration of varices is a safe and effective method for antenatal management of varices in women, prenatal obliteration results in less morbidity. On rare occasions, obliterated varices can bleed in subsequent pregnancies. Therefore, preconception evaluation of the state of varices prior to each pregnancy and their ligation are important aspects of counselling. A successful foetomaternal outcome is achievable with multidisciplinary backup in a tertiary care centre.

Keywords: EHPVO, EST, EVL, portal vein cavernoma, pregnancy outcome
Singapore Med J 2012; 53(10): 676–680

Sapuan J, Yam KF, Noorman MF, De Cruz PK, Abdul Razab WN, Rozali ZI, Sikkandar MF, Singh R
Correspondence: Clin A/Prof Rajesh Singh, rajesh.singh@monash.edu

ABSTRACT
Introduction Carpal tunnel syndrome (CTS) is a common pregnancy complication. However, it is often overlooked by medical practitioners and patients alike. This study aimed to describe CTS in relation to pregnancy and assess how significant the disease was among pregnant women.
Methods In a prospective cross-sectional study, 333 respondents were randomly selected from among pregnant women attending the primary care maternal health clinic in a university hospital. CTS was diagnosed clinically based on patient history and physical examination. The severity of CTS was assessed using the Boston Carpal Tunnel Questionnaire. Symptomatic respondents were asked whether they had mentioned their problems to doctors and received appropriate treatment.
Results 82 (24.6%) pregnant women presented with symptoms of CTS, a majority of whom were ethnic Malays (Malay 87.8%; non-Malay 12.2%). The risk for developing CTS during the third trimester of pregnancy was found to be two-fold among Malay women compared to patients of other ethnicities (odds ratio 2.262; 95% confidence interval 1.10–4.46; p = 0.024). The commonest complaint was daytime numbness (76.8%). The severity of CTS among patients was predominantly mild (80.5%), and the symptoms were severe enough to affect hand function in approximately one-third (34.1%) of the group. However, only 25.6% of symptomatic patients mentioned their problems to their doctors, and of these, 9.5% received treatment.
Conclusion CTS is prevalent in the third trimester of pregnancy, especially among Malay women, in whom the risk of developing the syndrome is two-fold. Yet, this troublesome complication of pregnancy appears to be under-recognised, with most patients not being treated appropriately.

Keywords: Caesarean section, maternal morbidity, perinatal morbidity
Singapore Med J 2012; 53(10): 671–675