This study provides Class IV evidence that for patients with T1DM and evidence of DSP, 12 months of seal oil omega-3 supplementation increases CNFL.

BackgroundOmega-3 polyunsaturated fatty acids (N-3) are essential nutrients for human health and integral components of neural tissues. There is evidence that N-3 supplementation may benefit exercise performance, however, no study has investigated the ergogenic potential of N-3 supplementation. Our objective was to determine the effect of short-term N-3 supplementation on neuromuscular-function and physical-performance in well-trained athletes.MethodsMale athletes (n = 30), 25 years (SD 4.6), training 17 h.wk−1 (SD 5) completed this randomized, placebo-controlled, parallel-design study. At baseline a blood sample was collected, maximal voluntary isometric contractions (MVC) with electromyography (EMG) recordings were measured, and participants underwent various performance tests including a Wingate test and 250 kJ time trial (TT) followed by repeated MVC and EMG measurement. Participants were then randomly assigned to receive N-3 (5 ml seal oil, 375 mg EPA, 230 mg DPA, 510 mg DHA) or placebo (5 ml olive oil) for 21-days after which baseline testing was repeated. The magnitude-based inference approach was used to estimate the probability that N-3 had a beneficial effect on neuromuscular-function and performance of at least ±1 %. Data are shown as mean ± 90 % confidence-interval.ResultsPlasma EPA was higher on N-3 than placebo (p = 0.004) but the increases in DPA and DHA were not significant (p = 0.087, p = 0.058). N-3 supplementation had an unclear effect on MVC force (4.1 ± 6.6 %) but increased vastus lateralis EMG by 20 ± 18 % vs placebo (very likely beneficial). N-3 supplementation reduced Wingate percent power drop by 4.76 ± 3.4 % vs placebo (very likely beneficial), but the difference in TT performance was unclear (−1.9 ± 4.8 %).ConclusionOur data indicates N-3 PUFA supplementation improved peripheral neuromuscular function and aspects of fatigue with an unclear effect on central neuromuscular function. Clinical trial registration NCT0201433.

Corneal nerve fiber length (CNFL) represents a biomarker for diabetic distal symmetric polyneuropathy (DSP). We aimed to determine the reference distribution of annual CNFL change, the prevalence of abnormal change in diabetes, and its associated clinical variables. RESEARCH DESIGN AND METHODSWe examined 590 participants with diabetes (399 with type 1 diabetes [T1D] and 191 with type 2 diabetes [T2D]) and 204 control patients without diabetes with at least 1 year of follow-up and classified them according to rapid corneal nerve fiber loss (RCNFL) if CNFL change was below the 5th percentile of the control patients without diabetes. RESULTSControl patients without diabetes were 37.9 6 19.8 years old, had median follow-up of three visits over 3.0 years, and mean annual change in CNFL was 20.1% (90% CI 25.9% to 5.0%). RCNFL was defined by values exceeding the 5th percentile of 6% loss. Participants with T1D were 39.9 6 18.7 years old, had median follow-up of three visits over 4.4 years, and mean annual change in CNFL was 20.8% (90% CI 214.0% to 9.9%). Participants with T2D were 60.4 6 8.2 years old, had median follow-up of three visits over 5.3 years, and mean annual change in CNFL was 20.2% (90% CI 214.1% to 14.3%). RCNFL prevalence was 17% overall and was similar by diabetes type (64 T1D [16.0%], 37 T2D [19.4%], P 5 0.31). RNCFL was more common in those with baseline DSP (47% vs. 30% in those without baseline DSP, P 5 0.001), which was associated with lower peroneal conduction velocity but not with baseline HbA 1c or its change over follow-up. CONCLUSIONSAn abnormally rapid loss of CNFL of 6% per year or more occurs in 17% of diabetes patients. RCNFL may identify patients at highest risk for the development and progression of DSP.Diabetic distal symmetric polyneuropathy (DSP) is one of the most prevalent and pervasive diabetes complications that is associated with morbidity and the frequent use of health care resources (1). The natural history of DSP begins with diffuse injury to small unmyelinated sensory nerves (Ad and C fibers) that include autonomic nerves and those that innervate the skin for conveying pain and temperature sensation. It is generally believed that nerve injury first occurs asymptomatically to small nerve fibers before progressing to involve large nerve fibers (2). While nerve conductions studies

OBJECTIVE Corneal nerve fiber length (CNFL) has been shown in research studies to identify diabetic peripheral neuropathy (DPN). In this longitudinal diagnostic study, we assessed the ability of CNFL to predict the development of DPN. RESEARCH DESIGN AND METHODS From a multinational cohort of 998 participants with type 1 and type 2 diabetes, we studied the subset of 261 participants who were free of DPN at baseline and completed at least 4 years of follow-up for incident DPN. The predictive validity of CNFL for the development of DPN was determined using time-dependent receiver operating characteristic (ROC) curves. RESULTS A total of 203 participants had type 1 and 58 had type 2 diabetes. Mean follow-up time was 5.8 years (interquartile range 4.2–7.0). New-onset DPN occurred in 60 participants (23%; 4.29 events per 100 person-years). Participants who developed DPN were older and had a higher prevalence of type 2 diabetes, higher BMI, and longer duration of diabetes. The baseline electrophysiology and corneal confocal microscopy parameters were in the normal range but were all significantly lower in participants who developed DPN. The time-dependent area under the ROC curve for CNFL ranged between 0.61 and 0.69 for years 1–5 and was 0.80 at year 6. The optimal diagnostic threshold for a baseline CNFL of 14.1 mm/mm2 was associated with 67% sensitivity, 71% specificity, and a hazard ratio of 2.95 (95% CI 1.70–5.11; P < 0.001) for new-onset DPN. CONCLUSIONS CNFL showed good predictive validity for identifying patients at higher risk of developing DPN ∼6 years in the future.