Association of maternal folate and B12 vitamin status with gestational diabetes mellitus: Still an open issue.

OBJECTIVES: There is conflicting evidence about the role of folate and B12in gestational diabetes mellitus (GDM) onset. The association of vitamin status with GDM was therefore revalued, also measuring the B12active form holotranscobalamin. METHODS: 677 women were evaluated at 24-28 weeks of gestation when OGTT was carried out. The 'one-step' strategy was employed for GDM diagnosis. Odds ratio (OR) of having GDM was estimated to quantify the association with vitamin levels. RESULTS: 180 women (26.6%) had GDM. They were older (median, 34.6 vs. 33.3 years, p = 0.019) and had higher body mass index (BMI) (25.8 vs. 24.1 kg/m2, p < 0.001). Multiparous women had lower levels of all evaluated micronutrients, while overweight lowered both folate and total B12, but not holotranscobalamin. Lower total B12(270 vs. 290 ng/L, p = 0.005), but not holotranscobalamin, was observed in GDM, being weakly negatively correlated with fasting glycemia (r = -0.11, p = 0.005) and 1-h OGTT serum insulin (r = -0.09, p = 0.014). At multivariate analysis, age, BMI and multiparity remained the strongest GDM predictors, while total B12(but not holotranscobalamin and folate) showed a slight protective effect (OR = 0.996, p = 0.038). CONCLUSIONS: A weak association between total B12 levels and GDM risk was shown, but it was not confirmed when holotranscobalamin was measured.

Incidence and status of insulin secretion in pregnant women with flat plasma glucose profiles during oral glucose tolerance test.

OBJECTIVES: Flat shaped glucose curves (FC) during oral glucose tolerance test (OGTT) in pregnant women (PW) are a not uncommon finding. We aimed to define the FC incidence in a large PW cohort and to describe the status of insulin and C-peptide secretion in women with FC when compared with a well-matched control group. METHODS: 1050 PW performing OGTT for gestational diabetes screening were enrolled. An increase <6 % in plasma glucose (PG) during OGTT defined a FC. Serum samples for measuring insulin and C-peptide were also obtained. RESULTS: 61 (5.8 %) women showed a FC. 60 of them, paired to a group of 60 no-FC women matched for age, body mass index and gestational age, were further investigated. C-peptide and insulin concentrations were significantly lower (P < 0.001) in FC in both 1-h and 2-h OGTT samples. When incremental area under the curves (AUC) normalized to PG were estimated, only AUCinsulin remained however significantly lower. The insulin sensitivity index was higher in FC. CONCLUSIONS: PW with FC showed a hypersensitivity to insulin with normal ß-cell function. Moreover, a delayed glucose absorption could be hypothesised because of the slight but continuously increasing shape of insulin curve found in FC group. Both phenomena could occur in parallel and contribute to FC.

Pursuing appropriateness of laboratory tests: a 15-year experience in an academic medical institution.

Appropriateness in Laboratory Medicine has been the object of various types of interventions. From published experiences, it is now clear that to effectively manage the laboratory test demand it is recommended to activate evidence-based preventative strategies stopping inappropriate requests before they can reach the laboratory. To guarantee appropriate laboratory test utilization, healthcare institutions should implement and optimize a computerized provider order entry (CPOE), exploiting the potential of electronic requesting as "enabling factor" for reinforcing appropriateness and sustaining its effects over time. In our academic institution, over the last 15 years, our medical laboratory has enforced various interventions to improve test appropriateness, all directly or indirectly based on CPOE use. The following types of intervention were implemented: (1) applying specific recommendations supported by monitoring by CPOE as well as a continuous consultation with clinicians (tumour markers); (2) removing outdated tests and avoiding redundant duplications (cardiac markers, pancreatic enzymes); (3) order restraints to selected wards and gating policy (procalcitonin, B-type natriuretic peptide, homocysteine); (4) reflex testing (bilirubin fractions, free prostate-specific antigen, aminotransferases, magnesium in hypocalcemia); and (5) minimum retesting interval (D-Dimer, vitamin B12, C-reactive protein, γ-glutamyltranspeptidase). In this paper, we reviewed these interventions and summarized their outcomes primarily related to the changes in total test volumes and cost savings, without neglecting patient safety. Our experience confirmed that laboratory professionals have an irreplaceable role as "stewards" in designing, implementing, evaluating, and maintaining interventions focused to improving test appropriateness.

'Penelope test': a practical instrument for checking appropriateness of laboratory tests.

In medical laboratories, the appropriateness challenge directly revolves around the laboratory test and its proper selection, data analysis, and result reporting. However, laboratories have also a role in the appropriate management of those phases of total testing process (TTP) that traditionally are not under their direct control. So that, the laboratory obligation to act along the entire TTP is now widely accepted in order to achieve better care management. Because of the large number of variables involved in the overall TTP structure, it is difficult to monitor appropriateness in real time. However, it is possible to retrospectively reconstruct the body of the clinical process involved in the management of a specific laboratory test to track key passages that may be defective or incomplete in terms of appropriateness. Here we proposed an appropriateness check-list scheme along the TTP chain to be potentially applied to any laboratory test. This scheme consists of a series of questions that healthcare professionals should answer to achieve laboratory test appropriateness. In the system, even a single lacking answer may compromise the integrity of all appropriateness evaluation process as the inability to answer may involve a significant deviation from the optimal trajectory, which compromise the test appropriateness and the quality of subsequent steps. Using two examples of the check-list application, we showed that the proposed instrument may offer an objective help to avoid inappropriate use of laboratory tests in an integrated way involving both laboratory professionals and user clinicians.

Impact of optimizing pre-analytical phase on the diagnosis of gestational diabetes and related outcomes.

OBJECTIVES: Pre-analytical plasma glucose (PG) sampling methodology may significantly affect gestational diabetes mellitus (GDM) incidence, but no studies directly examined the impact on perinatal outcomes. We compared the effect on oral glucose tolerance test (OGTT) results of using for blood sampling the traditional sodium fluoride (NaF) tubes, batched at controlled temperature, and the more effective citrate-buffered tubes, in terms of GDM diagnosis and related outcomes. METHODS: We evaluated 578 pregnant women performing OGTT between 24- and 28-weeks' gestation. Paired NaF and citrate blood samples were drawn and analyzed for PG. GDM diagnosis was made by applying the 'one-step' American Diabetes Association strategy. Data on perinatal outcomes were collected in a subset of 330 women who delivered in our hospital network. RESULTS: Using the standard NaF approach, 69 (11.9%) GDM women were detected. Using citrate PG values, 90 women were additionally identified as GDM, increasing the GDM prevalence to 27.5%. Perinatal outcomes were analyzed according to the different diagnostic allocation (NaF-diagnosed GDM, additional citrate-diagnosed GDM, and no GDM). NaF-diagnosed GDM showed a higher incidence of large for gestational age (LGA) (p=0.034), and of cesarean and preterm delivery (p<0.01) vs. no GDM. The only outcome remaining more frequent in the additional citrate diagnosed GDM when compared with no GDM group was LGA (17.2 vs. 6.8%, p=0.025). CONCLUSIONS: If a health care system plans to use citrate tubes for GDM diagnosis, considerations about clinical implications are mandatory by balancing higher sensitivity in detecting a poor glycemic control with effects on outcomes to avoid "overdiagnosis".

Total laboratory automation: Do stat tests still matter?

During the past decades the healthcare systems have rapidly changed and today hospital care is primarily advocated for critical patients and acute treatments, for which laboratory test results are crucial and need to be always reported in predictably short turnaround time (TAT). Laboratories in the hospital setting can face this challenge by changing their organization from a compartmentalized laboratory department toward a decision making-based laboratory department. This requires the implementation of a core laboratory, that exploits total laboratory automation (TLA) using technological innovation in analytical platforms, track systems and information technology, including middleware, and a number of satellite specialized laboratory sections cooperating with care teams for specific medical conditions. In this laboratory department model, the short TAT for all first-line tests performed by TLA in the core laboratory represents the key paradigm, where no more stat testing is required because all samples are handled in real-time and (auto)validated results dispatched in a time that fulfills clinical needs. To optimally reach this goal, laboratories should be actively involved in managing all the steps covering the total examination process, speeding up also extra-laboratory phases, such sample delivery. Furthermore, to warrant effectiveness and not only efficiency, all the processes, e.g. specimen integrity check, should be managed by middleware through a predefined set of rules defined in light of the clinical governance.

Heparinate but not serum tubes are susceptible to hemolysis by pneumatic tube transportation.

BACKGROUND: Pneumatic tube transportation (PTT) may induce hemolysis (H) in blood samples. We aimed to compare the H degree before and after PTT implementation in our hospital. METHODS: Hemolysis indices (HI) for all lithium-heparin plasma samples (P) drawn by the Emergency Department in 2-month periods were retrospectively collected and pre- (n=3579) and post-PTT (n=3469) results compared. The impact of PTT introduction was investigated on LDH [HI threshold (HIt), 25], conjugated bilirubin (cBIL) (HIt, 30), K (HIt, 100) and ALT (HIt, 125). In addition, HI retrieved for P and paired serum samples collected in silica clot activator tubes (S) from the same venipuncture were compared in pre- (n=501) and post-PTT (n=509) periods. RESULTS: Median (5-95th percentile) HI in P was significantly higher in post-PTT period [7 (0-112) vs. 6 (0-82), p<0.001]. Results reported as 'Hemolysis' in P increased from 6.6% in pre-PTT to 9.4% in post-PTT (p<0.001). Investigated tests gave the following rejection rates (pre-PTT vs. post-PTT): LDH, 13.4% vs. 18.8%, p<0.001; cBIL, 9.4% vs. 27.0%, p<0.05; K, 3.7% vs. 5.6%, p<0.001; ALT, 2.9% vs. 4.4%, p<0.01. The slightly higher susceptibility to H of S compared to paired P found in the pre-PTT [9 (1-64) vs. 6 (0-85)] was not confirmed in the post-PTT period [7 (0-90) vs. 8 (1-72)], in which median HI in S was significantly lower (p<0.001) than in pre-PTT. CONCLUSIONS: In our setting PTT promotes H in P, increasing the rate of rejected tests. The use of S appears to protect against the hemolysing effect of PTT.

Frequency of Pancreatic Hyperamylasemia in Human Immunodeficiency Virus-Positive Patients in the Highly Active Antiretroviral Therapy Era.

OBJECTIVES: Increased frequency of hyperamylasemia has previously been reported in human immunodeficiency virus (HIV)-positive patients, but studies determined total amylase activity and were performed before the introduction of highly active antiretroviral therapy (HAART). We evaluated the frequency of pancreatic hyperamylasemia in a large HIV+ population mostly treated with HAART. METHODS: The upper reference limit (URL) for pancreatic amylase (P-AMY) was derived from 299 healthy blood donors. A cross-sectional study was then performed on samples obtained from 1,548 consecutive patients referred to our infectious disease clinic to assess serum P-AMY and lipase concentrations. Of the patients, 94% were HIV+, and most (92%) were taking HAART (HIV+Tx+). RESULTS: P-AMY URL was 51 U/L. The frequency of P-AMY increase did not significantly differ between HIV+ and HIV - populations (14.2% vs 15.2%, P = .91) or between HIV+Tx+ and HIV+Tx - (14.7% vs 8.9%, P = .11). In almost half (48.3% of HIV+ and 42.9% of HIV -) of hyperamylasemic patients, lipase was normal, indicating a non pancreatic origin of their P-AMY increase. Markedly elevated P-AMY (>3 times the URL) was found in six HIV+ patients and in one HIV - patient: two had macroamylasemia, one acute pancreatitis, three (including the HIV - patient) chronic pancreatitis, and one chronic hyperamylasemia of undefined origin. CONCLUSIONS: In our study, both HIV+ and HIV+Tx+ do not show an increased frequency of P-AMY elevation. Frank pancreatic disease is rare in this clinical setting.