The bidirectional longitudinal association between depressive symptoms and HbA<sub>1c</sub>: A systematic review and meta‐analysis
Magdalena Beran, Rutendo Muzambi, Anouk F.J. Geraets, Juan Rafael Albertorio‐Diaz, Marcel C. Adriaanse, Marjolein M. Iversen, Andrzej Kokoszka, Giesje Nefs, Arie Nouwen, Frans Pouwer, Jörg Huber, Andreas Schmitt, Miranda T. Schram
Abstract
Abstract Aim To investigate whether there is a bidirectional longitudinal association of depression with HbA 1c . Methods We conducted a systematic literature search in PubMed, PsycINFO, CINAHL and EMBASE for observational, longitudinal studies published from January 2000 to September 2020, assessing the association between depression and HbA 1c in adults. We assessed study quality with the Newcastle‐Ottawa‐Scale. Pooled effect estimates were reported as partial correlation coefficients (r p ) or odds ratios (OR). Results We retrieved 1642 studies; 26 studies were included in the systematic review and eleven in the meta‐analysis. Most studies (16/26) focused on type 2 diabetes. Study quality was rated as good (n = 19), fair (n = 2) and poor (n = 5). Of the meta‐analysed studies, six investigated the longitudinal association between self‐reported depressive symptoms and HbA 1c and five the reverse longitudinal association, with a combined sample size of n = 48,793 and a mean follow‐up of 2 years. Higher levels of baseline depressive symptoms were associated with subsequent higher levels of HbA 1c (partial r = 0.07; [95% CI 0.03, 0.12]; I 2 38%). Higher baseline HbA 1c values were also associated with 18% increased risk of (probable) depression (OR = 1.18; [95% CI 1.12,1.25]; I 2 0.0%). Conclusions Our findings support a bidirectional longitudinal association between depressive symptoms and HbA 1c . However, the observed effect sizes were small and future research in large‐scale longitudinal studies is needed to confirm this association. Future studies should investigate the role of type of diabetes and depression, diabetes distress and diabetes self‐management behaviours. Our results may have clinical implications, as depressive symptoms and HbA 1c levels could be targeted concurrently in the prevention and treatment of diabetes and depression. Registration PROSPERO ID CRD42019147551.