Is there glycemic threshold for mortality risk?

OBJECTIVE - To determine whether there are thresholds for fasting and for 2 -h glucose above which the risk of death from all causes and from coronary heart disease (CHD) increases. RESEARCH DESIGN AND METHODS - We studied 23-year mortality data from the Pa ris Prospective Study of the 7,018 men, aged 44-55 years, who were not know n as diabetic at the baseline examination. The effect of glucose concentrat ions on mortality was studied using the observed relative risks and an age- adjusted Cox proportional hazards model. RESULTS - For all causes of death, there were J-shaped relationships with b oth fasting and 2-h glucose concentrations, and the lowest observed death r ates were in the intervals centered on 5.5 mmol/l for fasting glucose and 5 .0 mmol/l for 2-h glucose. The death rates for CHD were low in this populat ion: for fasting glucose, the hazards ratio was best modeled by a positive linear relationship; for 2-h glucose, it was modeled by a J-shaped curve an d the lowest observed death rate was in the interval centered on 6.0 mmol/l . CONCLUSIONS - In the Paris Prospective Study, there were no clear threshold s for fasting or 2-h glucose concentrations above which mortality sharply i ncreased; in the upper levels of the glucose distributions, the risk of dea th progressively increased with increasing fasting and 2-h glucose concentr ations.