COVID-19 lockdown affects glycaemic parameters in patients with diabetes

In a systematic review and meta-analysis, glycaemic parameters in patients with type 1 diabetes (T1D) improved during the COVID-19 lockdown periods. Conversely, patients with type 2 diabetes (T2D) had short-term worsening of glycaemic values.

“COVID-19 lockdown and the associated measures and restrictions led to a change in healthcare and in people’s everyday lives, and had an impact on diabetes management. Our results demonstrate that the effects of pandemic lockdown on T1D and T2D were very different,” said the researchers.

T1D: Improved glycaemic parameters

Twenty-five T1D studies were included (n=2,881). On pooled analysis of 11 studies, Hb_A1c values dropped compared with pre-lockdown measurements (mean difference, −0.05). In eight studies, significant improvements in Hb_A1c levels due to ‘lockdown effect’ ranged between −0.1 and −0.3 percent (p<0.05). [Diabetol Metab Syndr 2021;doi:10.1186/s13098-021-00705-9]

Time in range also improved based on a pooled analysis of 18 studies (mean difference, +3.75 percent), with significance being achieved in 15 studies (p<0.05).

“[Lockdowns may have allowed for] more time for self-care and … to concentrate on T1D management. [In children, parents] forced to stay home [may have had] more time to deal with the disease, [hence becoming] more attentive to diabetes management,” noted the researchers.

Lockdowns may have also afforded a more regular routine, including scheduled and balanced meals. [Diabetes Res Clin Pract 2020;167:108354; Diabetes Care 2020;43:e88-89] Individuals also have more time to exercise to compensate for physical inactivity. [J Endocr Soc 2020;4:bvaa149]

“[Moreover,] in almost all cases, T1D patients had digital diabetes management available during the lockdown … [These] probably had a positive impact on glycaemic control,” the researchers noted. While digital approaches are reportedly promising, the focus of T1D treatment is still insulin therapy. [J Med Internet Res 2020;23:e23475; J Med Internet Res 2020;23:e23244]

T2D: Hb_A1c deterioration

Meta-analysis of eight studies on T2D (n=1,823) revealed that lockdowns were associated with Hb_A1c deterioration (mean difference, +0.14). Four studies showed Hb_A1c deteriorations, two of which presenting significant values (p=0.02 and p=0.002).

The long periods of confinement may have encouraged cravings for calorie-dense and sugary foods and frequent snacking, leading to metabolic disturbances and weight gain. [Diagnosis 2020;7:85-90; Nutrients 2020;12:2327] Other factors that might be accountable for the Hb_A1c deterioration are physical inactivity, increased sedentary time, insufficient sleep, socio-economic issues that could have affected food alternatives, and increased stress and anxiety. [Prim Care Diabetes 2021;15:424-427; Acta Diabetol 2020;58:431-436; Diabetes Metab Syndr 2020;14:1963-1966]

Lifestyle changes are important

Restrictions across countries are different, and lockdowns took place at different periods of time from country to country, with varying lengths and strictness. The studies included in the review also have different investigation periods – with some observing the impact during lockdown, while others looking into the effects after the lockdown. T1D and T2D also have contrasting pathogenesis that warrant different treatment approaches.

Despite these heterogenous factors, a common ground for both T1D and T2D management is the effect of lifestyle change on glycaemic control. “[Improving Hb_A1c levels is important in diabetes because it] reduces the risk of comorbidities and complications, as well as progressions of micro- and macrovascular consequences,” said the researchers.

Several limitations must be taken into context. Apart from including only English and German studies, only a few T2D studies were included. Some studies may also be lacking detailed analyses, as most COVID-19 trials are published quickly and are simplified to make information available to help inform treatment decisions. “[Moreover,] local lockdown measures and restrictions are heterogeneous, and we could only evaluate the current data situation,” they said.

Further investigation is thus warranted to include larger samples, detailed analyses of other parameters, and data from other countries to ascertain the ‘lockdown effect’ of diabetes on a wider scale.