Incorrect response to the REST call using node.js

I have the following api :

for (var index in workload.elements) {
    (function(index) {
        var arr = [];
        var resourceIdentifiers = {};
        var elementinfo = {};
        var metadataModified = {};

        elementinfo = workload.elements[index];

        arr[index] = workload.elements[index].uri;

        if (workload.elements[index].parameters.imageUri) {
            arr.push(workload.elements[index].parameters.imageUri);
        }

        resourceIdentifiers = arr.join(',');

        console.log('uri' + resourceIdentifiers);

        mysql.elementlevelpricing(resourceIdentifiers, function(result) {

            elementlevelpricingSummary = result;

            metadataModified = workload.elements[index].metadata;

            metadataModified.pricingsummary = elementlevelpricingSummary;
            delete elementinfo.metadata;

            elementinfo.metadata = metadataModified;

            workloadinfo.elements = JSON.stringify(elementArray, null, 2);

            elementArray[index] = elementinfo;

            console.log(JSON.stringify(elementArray, null, 2));

            res.send(JSON.stringify(elementArray, null, 2));

        });

    })(index);
}

console.log prints the correct result , but the response to the REST call is incorrect and getting the result of only one the value getting into the loop.