New criteria for impaired fasting glucose and screening for diabetes in cystic fibrosis: Fig. 1—

Abstract

Cystic fibrosis-related diabetes mellitus (CFRD) is the most frequent comorbidity in cystic fibrosis. Its clinical relevance is stressed by the association with increased mortality, and decreased pulmonary and nutritional status. An annual oral glucose tolerance test (OGTT) is recommended as a screening test for CFRD, but this is often not realised because of its time-and resource-consuming nature. Therefore, alternative approaches are welcome.In 2003 ). The current authors tested whether this approach was reliable for the early identification of patients with CFRD.OGTTs from 1,128 patients (53% males; 47% females; median age 17.1 yrs) were available for analysis. A total of 101 (8.9%) OGTTs were classified as diabetic. The new ADA criteria for IFG increased the sensitivity to 82% (versus 65%) and decreased the specificity to 70% (versus 94%) compared with the old criteria used to identify patients with diabetic OGTTs.In conclusion, the American Diabetes Association approach of using impaired fasting glucose as an indication for performing selective oral glucose tolerance tests is definitely unsuitable when aiming at the early identification of patients with cystic fibrosis-related diabetes mellitus, and it cannot replace annual oral glucose tolerance tests.

Spontaneous hypoglycemia in patients with cystic fibrosis

“…According to an European meta-analysis of type 2 diabetes, the diabetes diagnoses based on 2 h-OGTT glucose concentrations without fasting hyperglycemia were frequent (46), but median FPG (109 mg/dl (6.0 mmol/l)) was much higher than in our CF patients (87 mg/dl (4.8 mmol/l)). These results strengthen the notion that the diagnosis of CFRD should rely upon yearly OGTT (14), since low FPG levels do not exclude it.…”

“…A unique feature of CFRD is that, postabsorptively, so many patients are normoglycemic (13) that the most recent diagnostic criteria for diabetes based on fasting plasma glucose (FPG) are not sensitive enough (14). The association of diabetic glucose tolerance with such low FPG is unusual in other forms of diabetes (15).…”

Screening for cystic fibrosis-related diabetes: a systematic review.

“…Nine studies 174,[183][184][185][186][187][188][189]205 (one in German 174 ) provided sufficient data for 2 × 2 tables with actual numbers, not just per cent, so that CIs could be produced. Full details are given in the data extraction forms in Appendix 4.…”

“…Mueller-Brandes et al 205 note that the OGTT is not a gold standard because of its poor reproducibility. They note the need for a confirmatory test but report that only 47% of those with a positive OGTT (34 out of 73 patients) had this confirmed by a repeat OGTT.…”

“…In one of the largest studies, Mueller-Brandes et al 205 used data from OGTTs in 1128 patients to assess the value of FPG alone. The FPG was at two levels, using the old and new ADA definitions for elevated glucose: ≥ 6.1 mmol/l and ≥ 5.6 mmol/l, respectively ( Table 18).…”