Journal of Human Reproductive Sciences

ORIGINAL ARTICLE
Year
: 2011  |  Volume : 4  |  Issue : 1  |  Page : 20--22

Efficacy of 2-hour post glucose insulin levels in predicting insulin resistance in polycystic ovarian syndrome with infertility


Pikee Saxena1, Anupam Prakash2, Aruna Nigam1,  
1 Department of Obstetrics and Gynecology, Lady Hardinge Medical College and Smt. Sucheta Kriplani Hospital, New Delhi, India
2 Department of Medicine, Lady Hardinge Medical College and Smt. Sucheta Kriplani Hospital, New Delhi, India

Correspondence Address:
Pikee Saxena
Department of Obstetrics & Gynecology, LHMC & SSKH, J-36, Saket, New Delhi - 110 017
India

Abstract

Background : Insulin resistance (IR) is central to the pathogenesis of polycystic ovarian syndrome (PCOS), but tests for determining IR are elaborate, tedious and expensive. Aims : To evaluate if DQ2-hour post-glucose insulin levelDQ is an effective indicator of IR and can aid in diagnosing IR in infertile PCOS women. Settings and Design : Observational study at infertility clinic of a tertiary care center. Materials and Methods : 50 infertile women with PCOS and 20 females with tubal/male factor infertility were evaluated for the presence of IR, as defined by the fasting/2-hour post-glucose insulin levels cutoffs of >25/>41 μU/mL, respectively. The clinical, metabolic and endocrinologic profile was determined in both the groups. Statistical Analysis : Statistical analysis was performed using SPSS (Chicago, IL, USA). Results : Body mass index, post load glucose, insulin, glucose/insulin ratio, area under curve (AUC) of glucose and insulin and insulinogenic index were significantly lower in the controls as compared to the PCOS group. DQ2-hour post-glucose insulin levelsDQ were elevated in 88% of PCOS individuals but were normal in all females not suffering from PCOS. These levels significantly correlated with AUC of glucose and insulin, and insulinogenic index and inversely correlated with 2-hour glucose to insulin ratio (r=0.827, 0.749 and −0.732, respectively). Conclusions : DQ2-hour post-glucose insulin levelsDQ appears to be a good indicator of IR. It can be a useful tool, especially in low resource setting where a single sample can confirm the diagnosis, thus reducing cost and repeat visits.



How to cite this article:
Saxena P, Prakash A, Nigam A. Efficacy of 2-hour post glucose insulin levels in predicting insulin resistance in polycystic ovarian syndrome with infertility.J Hum Reprod Sci 2011;4:20-22


How to cite this URL:
Saxena P, Prakash A, Nigam A. Efficacy of 2-hour post glucose insulin levels in predicting insulin resistance in polycystic ovarian syndrome with infertility. J Hum Reprod Sci [serial online] 2011 [cited 2019 Jul 23 ];4:20-22
Available from: http://www.jhrsonline.org/text.asp?2011/4/1/20/82355


Full Text

 Introduction



Polycystic ovarian syndrome (PCOS) is a multisystem endocrinopathy occurring in women of reproductive age group. Insulin resistance (IR) is a major factor in the development of PCOS, and the resulting hyperinsulinemia plays a role in the pathogenesis of reproductive disorders. [1],[2]

It is important for the physicians to identify women with PCOS having IR so that therapeutic intervention can be initiated with insulin sensitizers since it results in clinical and metabolic improvement. Although there are many elaborate, expensive and tedious techniques available for evaluating IR, however, in resource-constrained developing countries, these tests are not widely accessible. Therefore, a single and reliable test to screen for IR is essential. This study was planned to ascertain whether "2-hour post-glucose insulin level" can be used as a cost-effective, convenient and reliable indicator to diagnose insulin resistance, which holds the key to the pathogenesis of PCOS.

 Materials and Methods



Subject selection criteria

This observational clinical study was performed in an infertility clinic of a tertiary care center where consecutive 50 patients with PCOS and 20 controls were evaluated after a written informed consent was obtained from them. Patients were labeled as having PCOS [3] if any two out of the following three criteria were present: 1) oligo- or anovulation, 2) clinical and/or biochemical signs of hyperandrogenism, and 3) polycystic ovaries on sonography with exclusion of other etiologies. Patients in the control group included women with tubal/male factor infertility with no evidence of anovulation.

Women with associated diabetes mellitus, those on steroid hormones, on drugs known to have effects on lipid metabolism during the past 2 years, and of age <18 years or >38 years not included in the study. Clinical evaluation of each patient included detailed clinical history comprising menstrual, obstetric and personal past, family, and treatment history, followed by focused physical examination. Ferriman Gallwey scoring of ≥7 was used for grading hirsutism. [3] Anthropometric measurements were made by the same observer to obviate interobserver variation. Pelvic ultrasound (both transabdominal and transvaginal) was performed to record the status of ovaries, uterus and adnexa. Ovaries were carefully evaluated for multiple (>10) immature follicles of 2-8 mm diameter and stromal hyperplasia with/without hyperemia. Endometrial thickness was also measured in the early follicular phase.

Sample collection and estimation

Patients were advised to have carbohydrate diet of at least 300 g for 3 days prior to the test. The fasting blood sample was analyzed for serum lipid profile, follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), prolactin and testosterone on day 2 or 3 of menstrual cycle, while serum progesterone was measured on day 21. Blood sugar values and serum insulin values were determined during a 75 g oral glucose tolerance test (OGTT). Values of OGTT were assessed according to WHO, 2002. [4] Presence of IR was defined by fasting or post-load insulin levels >25 and >41 μU/mL, respectively (DRG diagnostic instrument, GmbH, Germany). These levels have been calculated after calibration of the kits and standardizing the kits for many years. Area under curve (AUC) for glucose and insulin during OGTT, Insulinogenic Index (AUCi/AUCg), fasting and 2-hour glucose to insulin ratio were charted as determinants of IR in these patients. Hormonal estimation was done by chemiluminescence assay. Lipid profile was estimated by using enzymatic colorimetric technique and criteria adopted were in consonance with the NCEP-ATP III guidelines. [5]

Statistical analysis

The statistical analysis was performed using SPSS (Chicago, IL, USA). Clinical, hormonal and metabolic parameters were compared between the PCOS and the control groups, employing the two-tailed unpaired student's t test. To identify whether "2-hour post-glucose load insulin levels" correlated significantly with fasting and 2 hours glucose/insulin ratio, AUC of glucose and insulin and insulinogenic index, correlation between different variables was determined using Pearson's coefficient of correlation. P value <0.05 was taken as the cut-off level for significance.

 Results



The prevalence of various clinical features in the two groups is given in [Table 1]. In the PCOS group, 18% patients had a family history of diabetes as against 5% controls, 8% had impaired glucose tolerance as against none in controls and 32% had deranged serum lipids as against 10% in the control group. The hormonal and metabolic parameters are also outlined in [Table 2] and [Table 3], respectively. The hormonal profile of all subjects in the control group was in the normal range. Body mass index (BMI), 2-hour glucose, fasting and 2-hour insulin, AUC of glucose and insulin, insulinogenic index and 2-hour glucose/insulin ratios were significantly higher in the PCOS patients as compared to the controls.{Table 1}{Table 2}{Table 3}

In the PCOS group, there were 16 lean (BMI<25) and 34 obese (BMI>25) subjects. It was observed that fasting insulin level >25 μU/mL was present in 4 (8%; obese PCOS) and postprandial insulin of >41 μU/mL was present in 44 (88%; 15 lean and 29 obese PCOS) patients, i.e. 88% had IR. All four patients with fasting insulin >25 μU/mL also had higher (>41 μU/mL) postprandial insulin levels. The hormonal and metabolic profile of lean and obese PCOS patients was comparable. "2-hour post-glucose insulin levels" significantly correlated with AUC of glucose and insulin and insulinogenic index and inversely correlated with 2-hour glucose to insulin ratio (r=0.827, 0.749 and −0.732, respectively).

The PCOS group had significantly (P<0.05) higher serum triglycerides (133.6±37.2 vs. 90.16±31.6 mg/dL) and higher low density lipoprotein (LDL) cholesterol levels (113.8±45.6 vs. 98±37.1 mg/dL) but lower high density lipoprotein (HDL) cholesterol levels (42.4±27 vs. 55.2±31.4 mg/dL). Total cholesterol levels, however, did not differ between the two groups (173.6±45.5 vs. 170±43.5 mg/dL; P>0.05).

 Discussion



IR plays a key role in the pathogenesis of PCOS. For detecting IR, a number of techniques such as euglycemic clamp technique, [6] insulin tolerance test, [7] insulin sensitizing test, i.v./oral glucose tolerance test, [8] fasting insulin levels, [6] and fasting glucose to insulin ratio have been devised by several investigators. However, all these techniques are time consuming, expensive, stressful to the patients or are applicable to selective group of subjects and are not suitable for wider clinical use. Besides, the high cost and nonavailability of newer technologies is also a hindrance. Recently, "2-hour post-glucose insulin levels" has been recognized as a possible indicator of IR in the PCOS patients. [9] In this study, the "2-hour post-glucose insulin levels" in PCOS subjects was observed to correlate well with several parameters of insulin resistance (2 hours glucose/insulin ratio, AUC of glucose and insulin and also with the insulinogenic index), with the latter tests being more tedious, expensive and time consuming. In patients with normal glucose tolerance, values of glucose remain in the normal range due to adequate insulin response. A woman with IR, normal glycemic levels may be noticed after a glucose challenge because the pancreas will have to secrete excess insulin in order to keep the blood sugar in the normal range.

It was observed that insulin levels were significantly higher 2 hours after 75 g glucose load in PCOS subjects compared to fasting insulin levels and these levels correlated well with other parameters of insulin resistance. Therefore, a single "2-hour post-glucose insulin level" appears to be a reliable indicator of IR in PCOS patients.

 Acknowledgement



This paper was possible from a research grant from Department of Science and Technology.

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