The Gestational Diabetes Mellitus - Report Example

A critique of the paper entitled ‘Determinants of gestational diabetes mellitus: A case control study in a district tertiary care hospital in south India’. Name Course Name and Code Instructor’s Name Date The background of the study This is a critique of a study that was conducted to elucidate the some of the major risk factors for gestational diabetes mellitus (GDM). The study was based in Sri Avittom Thirunal Hospital, Thiruvananthapuram district, Kerala, South India. The study participants included 300 GDM women as cases and 300 age matched controls. The variables that were studied in the case control study included socio demographic characteristics, pre-pregnancy body mass index (BMI), menstrual history, obstetric history, infertility history, family history of diabetes in first degree relatives, recurrent urinary tract infection (UTI) and moniliasis. The study was conducted between August 2007 and June 2008. The methodology used The Glucose Test (GCT) at 24-28 and an Oral Glucose Tolerance Test (OGTT) with 100gm of glucose were used to group participants into case and control groups. The participant in the case group were those who developed glucose intolerance during a visit to the hospital while the control group included women who had a normal glucose challenge test (GCT) at 24-28 weeks, followed by a normal Oral Glucose Tolerance Test (OGTT) with 100gm of glucose (age matched control). The interpretation of the OGTT was interpreted by the National Diabetes Data Group values. The abnormal values that led to participant to be placed in case group were as follows: FBS ˃105 mg%, one hour ˃190mg%, two hours ˃165mg% and three hours ˃145mg%. It should be noted that only patients who showed two or more of these abnormal values were classified as gestational diabetic and hence placed in the case group. Women who had a diagnosis of diabetes prior to pregnancy were excluded from this study. After successful assessment of the GCT and OGTT the study assessed the following risk factors in the participants socio demographic characteristics, menstrual history, obstetric history (h/o previous pregnancy losses, macrosomia, congenital anomalies, prematurity, diabetes in previous pregnancy, preeclampsia, polyhydramnios), history of infertility, family history of diabetes in first degree relatives, recurrent urinary tract infection (UTI), moniliasis and premature labour pains. The participants underwent a complete general examination. The minimum sample for the study was calculated and found to be 215 for both cases and controls. The results from the study were analysed using SPSS version 12. The variables were compared using a t-test. A Chi square test and Odd’s ratio was also calculated. A P-value of ˂0.05 was considered to be statistically significant. The independent effects of each variable were analysed using multiple regression analysis and the Odd’s ratio was adjusted and 95% confidence was calculated from the logistic regression analysis. The results obtained The results indicated that of the women who attended prenatal clinic in Sri Avittom Thirunal Hospital, Thiruvananthapuram district, Kerala, South India between August 2007 and June 2008, 338 patients had diabetes complicating pregnancy. Of these, 38 had diabetes prior to pregnancy and hence were excluded from the study. The remaining 300 women were placed in the case group and compared with 300 age matched controls. The results of the study revealed that overweight and obese, increased pre-pregnancy body mass index (BMI), irregular menstrual cycle history, infertility history, family history of diabetes in first degree relatives especially maternal, a history of previous pregnancy losses, a history of preeclampsia, a history of recurrent urinary tract infection (UTI) and a history of moniliasis, a history of macrosomia in previous pregnancy and polyhydramnios were found to be independently associated with GDM. From the findings it was concluded that GDM is associated with several different modifiable and non modifiable risk factors. The adjusted odds ratios (OR) with 95% CI for various modifiable and non modifiable risk factors were as follows: pre-pregnancy BMI ≥25 OR was 2.7; history of infertility OR was 3.3; family history of diabetes OR was 4.5; polyhydroamnios OR was 6.0; UTI OR was 3.2 and moniliasis OR was 7.6. The p-values for all these risk factors was less than 0.05 implying that the correlation between these factors and GDM did not happen by chance. Thus, they were significantly associated with GDM. Critical appraisal of the work The present paper under critique had various good attributes and bad ones which are associated with epidemiological research. The strengths and limitations of the study are hereby discussed critically. Study question A study always has a study statement or study question which is used to identify issues to be studied in a research (Ferrara, 2007). For one to be able to formulate a research question which is strong he or she should be familiar with the field of research. In addition, he or she should be familiar with vital research questions in his or her area of study (Chu et al., 2007). The researcher should also be able to identify fields which require more research to be able to formulate a research question. The research question should be aimed at bringing more understanding to the field of study or filling a knowledge gap (Hedderson, Williams, Holt, Weiss and Ferrara, 2008). The researchers also need to know what has already been done in the field of study and what needs to be improved to be able to formulate a research question (Bhat, Ramesha, Sarma, Menon, Sowmini, and Kumar, 2010). The relevance of the study also is vital in the formulation of the research question. Finally, the significance of the knowledge gained in the proposed study should be considered to be able to formulate a research question (Schaefer-Graf, Graf, Kulbacka, Kjos, Dudenhausen, Vetter, and Herrera, 2008). The study question of the study was clearly focused. The study question was to elucidate some of the major risk factors for gestational diabetes mellitus (GDM). From this one can easily determine that the study will involve will involve unravelling of risk factors for GDM (Solomon et al., 1997). It is also easier for one to perceive that the study participants will mainly include pregnant women. It is also clear that the question sort to establish a relationship between certain risk factors and GDM. Thus, the study question was clearly specified in the study. Results The results provided in the paper clearly answer the study question. The authors have tried as much as possible to outline various risk factors and analysed their independent relationship to GDM using multivariate regression analysis (Ferrara, 2007). The authors’ Odds ratio was adjusted for all risk factors to reflect their independent association with GDM. However, the conclusion cited in the abstract does not reflect the intention of the study. The study may purpose was to elucidate the determinants of GDM. However, in the abstract the authors conclude that “early identification of women at risk of GDM and prompt treatment is recommended to prevent complications”. Clearly this conclusion does not answer the initial intention of the study. This is more of a recommendation than a conclusion (Chu et al., 2007). The authors could have highlighted the risk factors that determine the development of GDM in their conclusion instead of providing a recommendation of what ought to be done (Hedderson et al., 2008). Furthermore, even though the authors have clearly presented their findings in table forms to summarize their results analysis; the tables are not referred to anywhere in the text (Schaefer-Graf et al., 2008). The discussion and results section of the paper only gives the summary of their findings without referring to these tables (Bhat et al., 2010). This raises eyebrows as to whether the authors just threw the tables in the paper to fill space or what was their intention. Sampling The sampling method employed in the study is not clearly outlined. The study does not give a detailed description of selection criteria and only mentions those who were to be excluded from the study. The selection criteria for control group is especially lacking and only mentions that the control group included the next woman of the same age, who had a normal GCT at 24-28 weeks followed by a normal OGTT with 100gm of glucose (Chu et al., 2007). Question arises as to what happens if the next woman with these characteristics declines to provide the needed information or declines to participate in the study. Is she compelled to do so or will the investigators wait for another one. Study setting The study was only carried out in Sri Avittom Thirunal Hospital, Thiruvananthapuram district, Kerala, South India which may not be representative of what could be observed in other regions of India or even the world. This raises issues with the generalization of the authors’ in their concluding remarks about the determinants of GDM (Ferrara, 2007). It is possible that such results may not be a reflection of the general population since from discussion section of the paper some studies reported lack of association between some factors such as macrosomia with GDM. Thus generalization of the results to the general population might be misleading. Selection There is a possibility of selection biasness. The authors have admitted this in their concluding remarks that given that their study was hospital based case control study it could have been biased to certain extent (Hedderson et al., 2008). There is a possibility that women who had prior history of GDM or familial diabetes were likely to agree to participate in the study. it is also possible that during the time of measurement of GCT at 24-28 weeks and OGTT some women had not taken or had taken sugar increasing diets and that even the follow up measurement which required overnight fasting could not have been adhered to and resulted to elevated sugar level and hence making such patients to be wrongly grouped in case group (Bhat et al., 2010). Thus there is a possibility that some women were misclassified in the study. Ethical issues Studies involving human participants need to be conducted in an ethical framework (Ferrara, 2007). In particular such studies need to address three research ethics, namely; persons participating in the research need to be respected, minimization of risk to the participants and being just. Respecting participants ensures that participation is voluntary and autonomous (Chu et al., 2007). The study has not provided any information in relation to whether participation is voluntary and whether the information obtained from the participants were kept anonymous. It is not indicated whether consent was sort from the participants for them to be involved in the study. The authors of the article do not indicate whether they informed their participants of any risks that could have arisen during the study and the duration of the subject’s participation (Ray et al., 2001). It is also not indicated whether any ethical institutional review board approved the protocol used in the study to ensure that the study was being undertaken in an ethical manner (Hedderson et al., 2008). The fact that the study involved at some level phlebotomy to analyse blood for sugar levels almost three times in a span of three hours implies that there were some risks that would have arisen (Chen et al., 2009). Thus it would have been ethical for the participants to be informed of such likely risks. However, it is not indicated whether such issues were addressed (Bhat et al., 2010). It can be said that the risks of participation in the study were not spelt out to participants and hence the protocol violated the ethical values required in a study. There is need to fairly distribute risks and benefits that may result from a stud (Ferrara, 2007). This implies that any knowledge resulting from the research need to benefit the participants of the study. In this study the information regarding determinants of GDM is bound to benefit the pregnancy mothers by having risk factors established earlier and possible treatment commissioned before the problem is out of hand (Weijers, Bekedam, and Smulders, 2002). From this discussion it can be concluded that the study did not adhere to ethical standard of research to a large extent. Conclusion To greater extent the paper fulfilled the attributes of a case control study associated with epidemiological studies. The paper clearly identified the study problem and used it as guidance throughout the study. The study question seems to have guided sampling of participants, the collection of data, the discussion and to some extent the conclusion. However, the study conclusion especially that presented in the abstract is not a representation of the study question. Furthermore, the sampling technique used in the study had some limitations and was not clearly explained in the paper. The paper also failed to provide information on the participation criteria in addition to how ethical issues related to studies involving human subjects were addressed. Even though the study was carried out is a single hospital it is misleading for the authors to try to generalize their findings to the general population. This is because the result might not be replicated in other regions as exemplified in their discussion section where some factors were found not to be associated with GDM in studies conducted elsewhere. The study might also have been biased in selection of participants and there is a possibility that some study participants were misclassified in either case or control group. References Bhat, M., Ramesha, K., Sarma, S., Menon, S., Sowmini, C., and Kumar, G. 2010. Determinants of gestational diabetes mellitus: A case control study in a district tertiary care hospital in south India. Int J Diabetes Dev Ctries., vol. 30, no. 2,pp. 91–96. Chen, L., Hu, F., Yeung, E., Willett, W., and Zhang, C. 2009. Prospective Study of Pre-Gravid Sugar-Sweetened Beverage Consumption and the Risk of Gestational Diabetes Mellitus. Diabetes Care, vol. 32, no. 12, pp. 2236-2241 Chu, S., Callaghan, W., Kim, S., Schmid, C., Lau, J., England, L., and Dietz, P. 2007. Maternal Obesity and Risk of Gestational Diabetes Mellitus. Diabetes Care, vol. 30, no. 8, pp. 2070-2076 Ferrara, A. 2007. Increasing Prevalence of Gestational Diabetes Mellitus: A public health perspective. Diabetes Care, vol. 30, no. supplement 2, pp. S141-S146 Hedderson, M., Williams, M., Holt, V., Weiss, N., and Ferrara, A. 2008. Body mass index and weight gain prior to pregnancy and risk of gestational diabetes mellitus. American Journal of Obstetrics and Gynecology, vol. 198, no. 4, pp. 409.e1-409e7 Ray, J., Vermeulen, M., Shapiro, J., and Kenshole, A. 2001. Maternal and neonatal outcomes in pregestational and gestational diabetes mellitus, and the influence of maternal obesity and weight gain: the DEPOSIT study. QJM: An International Journal of Medicine, vol. 94, no. 7, pp. 347-356 Schaefer-Graf, U., Graf, K., Kulbacka, I., Kjos, S., Dudenhausen, J., Vetter, K., and Herrera, E. 2008. Maternal Lipids as Strong Determinants of Fetal Environment and Growth in Pregnancies with Gestational Diabetes Mellitus. Diabetes Care, vol. 31, no. 9, pp. 1858-1863 Solomon, CG., Willett, WC., Carey, VJ., Rich-Edwards, J., Hunter, DJ., Colditz, GA., Stampfer, MJ., Speizer, FE., Spiegelman, D., and Manson, JE. 1997. A prospective study of pregravid determinants of gestational diabetes mellitus. JAMA, vol. 278, no.13, pp.1078-83. Weijers, R., Bekedam, D., and Smulders, Y. 2002. Determinants of Mild Gestational Hyperglycemia and Gestational Diabetes Mellitus in a Large Dutch Multiethnic Cohort. Diabetes Care, vol. 25, no. 1, pp. 72-77 Weijers, RN., Bekedam, DJ., and Smulders, YM. 2002. Determinants of mild gestational hyperglycemia and gestational diabetes mellitus in a large Dutch multiethnic cohort. Diabetes Care, vol. 25, no. 1, pp. 72-7. Read More