Prepared by: Mark O'Doherty and Maria Hughes, UKCRC Centre of Excellence for Public Health, Queens University Belfast, United Kingdom
Details of collected information about glucose assessment in CHANCES cohorts are displayed in attached Excel file .
Seven cohorts can provide data: EPIC Elderly Bilthoven, EPIC Elderly Umeå, ESTHER, HAPIEE, RES, SENECA, Tromsø; and Zutphen. Repeated measurements are available for EPIC Elderly Bilthoven, EPIC Elderly Umeå, RES, Tromsø, and Zutphen. Of these seven cohorts with data at baseline, most have data for the total cohort. Exceptions are EPIC Elderly Bilthoven (see excel table) and HAPIEE (subsample of the Poland cohort only). As for repeated measures, the cohorts used similar methods between baseline and their recontacts for the collection, storage, and analysis of samples. Some differences were reported for RES (RSI had nonfasting samples taken at baseline but the other two cohorts and the subsequent recontacts for RSI used fasting samples. RS1-2 (1993-1995) did not have any blood measurements taken, so the first recontact for this cohort is RS1-3). The wiki description for Tromsø T3 states that glucose was measured but it is not included as part of the questionnaire response. Also, information for Zutphen recontacts 2 and 3 is missing so it is difficult to build an accurate picture of what is available for this cohort. However, it does appear that both plasma and serum were used, and both fasting and nonfasting samples were collected for glucose analysis between recontacts and baseline.
Most cohorts have used fasting samples (e.g. overnight). Exceptions to this are evident for ESTHER (fasting status not known for a proportion of participants), Zutphen (baseline) and Tromsø (baseline and recontacts). Fasting glucose measures are preferable as they can more readily be used to define persons with diabetes and hyperglycaemia (American Diabetes Association, 2011; World Health Organization, 2006). A random nonfasting glucose measurement ≥200 mg/dl (11.1 mmol/l) should only be used to define diabetes in patients with classic symptoms of hyperglycaemia or hyperglycaemic crisis (American Diabetes Association, 2011).
The cohorts that have currently provided the relevant information have used different biological samples (whole blood, plasma, and serum), storage (instant analysis and deep freeze) and analytical methods (missing for most cohorts) for the determination of glucose. Therefore, due to the many differences between cohorts and missing information, the comparability of the measurements is difficult to judge.
Table 5. Glucose
| Cohort BL | N | Recontact with data | n |
|---|---|---|---|
| EPIC Elderly Bilthoven | ? | R1 (1998-2002) | ? |
| EPIC Elderly Umeå | 3305 | 10yr follow-up | 3? |
| ESTHER | 9430 in total (8452 fasting) | none | - |
| HAPIEE | ? | none | - |
| RES (RSI-1) | >10,000 nonfasting | RS1-3 (1997-1999) RSI-4 (2002-2004) RSI-5 (ongoing) |
4000 2962 1613 |
| SENECA | 1830 | None | - |
| Tromsø T2 (1979-1980) | 16,548 | T3 (1986-1987) T4 (1994-1995) T5 (2001) |
? 7687 8000 |
| Zutphen | ~800 | R1 (1990) R2 (1993-1995)\R3 (2000) |
? ? ? |
| Total | ~ 41,913 + others (fasting & nonfasting) | ~ 11,690* + others |
* Only the recontact of each cohort was counted that was closest to the baseline measurement with respect to follow up duration. RSI shown for RES but full numbers for the other cohorts (RSII and RSIII) can be found in the excel table.
References
American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2011;34 Suppl 1:S62-9.
World Health Organization, 2006. Definition and diagnosis of diabetes mellitus and intermediate hyperglycemia : report of a WHO/IDF consultation. http://www.who.int/diabetes/publications/Definition%20and%20diagnosis%20of%20diabetes_new.pdf. Accessed 1st August 2011.
