A Study to Evaluate the Accuracy of Calculated Serum LDL Cholesterol Levels in Hypertriglyceridemic Individuals
Background: Farmers are vulnerable to a range of MSDs including osteoarthritis of the hip and knee, low back pain (LBP), upper limb disorders, and hand/arm vibration syndrome, as well as to the consequences of trauma such as sprains, fractures, and dislocations. The present study was conducted to assess prevalence of musculoskeletal disorders among agricultural workers in a known area.
Methods: A community based cross sectional study was done for a period of 3 months. The study included agricultural workers aged more than 20 years and 390 agricultural workers were selected. A pretested, structured, interviewer administered questionnaire was used for data collection. Modified Nordic musculoskeletal questionnaire was used for assessing the presence of musculoskeletal problem. The recorded data was compiled, and data analysis was done using SPSS Version 22.0 (SPSS Inc., Chicago, Illinois, USA).
Results: Pearson’s test for correlation shows a positive and significant correlation with the directly measured LDLc levels with all calculated values. But on application of two tailed t test only Chen’s method satisfied the null hypothesis question that the difference between the calculated and the directly measured LDLc level was zero. (r=0.923 with a p=0.000 and t=0.343 and p value of 0.732.)
Among the three groups defined on bases of TG:TC level only Modified Friedewald’s method showed a statistically significant r value and t value in group 1. (r=0.965 with p=0.000 and t=-1.056 with a p=0.296) No other group showed any statistically significant t value even though the r value was significant for all methods in all groups except for Hattori’s method in group 3.
Conclusion: Our study suggests that most commonly used methods of calculating LDLc fail in hypertriglyceridemics with TG levels over 400mg/dl. Our study also shows importance of t tests and Band Altman plot when comparing two diagnostic methods.
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